Genuine Lucas ignition switch

[Mike on Sea Hustler]

Good Morning all,

 

So the charging issues continue. As some may recall I have issues with the charging aboard Sea Hustler. Despite extensive work to try and sort the problem, it continues. Thus far the charging system has been rewired and separated from the domestic electricals so basically the alternator is connected directly to the starter battery with all new cables and avoids the torturous route it previously had through the electrical panel. This produced a charge but only at higher revs than I was happy running the engine and only on the single occasion after the installation was completed, - thoughts here of fitting the smaller alternator pulley which I have in stock.  Next time running the engine, nothing, not even at increased engine speed. Removed alternator to check connections and upon installation it charged perfectly putting out over 14v while I ran for an hour down to my local fuel berth. Stopped the engine to refuel and upon restarting, nothing, and nothing since. Removed alternator and replaced brushes, regulator and rectifier still nothing. Tried tensioning the belt to eliminate any possibility of slippage, nothing works. So turned my attention to the only remaining component that has thus far not been investigated fully- the ignition switch. Examination reveals that it is a Lucas 128AS, apparently common in BMC installations of the time and what was to be expected in a boat built in 1968. However, and it seems daft to say it now but while looking into this, I realised that despite it being a Lucas 128AS, it only has three positions, instead of the usual four, 1.off, 2 aux/run and 3. Start. My auto electrician did tell me that the pre heaters were energising during the cranking phase, but stupidly we did not make the connection. All the symptoms point toward the exciter circuit. He tells me that this should Not be an issue because the alternator should self excite once it is running BUT I THINK HE IS WRONG (even the experts can get it wrong sometimes) Google and ChatGPT both tell me that (in layman’s terms) if the pre heaters draw too much power  away from the exciter circuit during the initial cranking phase my ARC17/18 may well not be able to self energise afterwards. All this brings Me to the conclusion that I need to swap out this ignition switch. And this is a very lengthy way of bringing me to the question. I have looked at countless sites to find a suitable switch including Calcut Boats and they vary from cheap rubbish at £5.00 through to others at £70. I don’t want to gut a new switch that looks the part but simply stores up

problems for the future. Can someone tell me where I can get a genuine replacement that I can fit that will allow me to feel confident that at least i

have eliminate that component from the list of possible causes. I do not want to fit relays, diodes or tins of baked beans.

just a simple four position diesel engine ignition switch but one that will handle the power and not give me problems down the line. 
 

phew all that for one simple question. But at least I think i have explained the entire problem as we know it 

[pearley]

[Tony Brooks]

On a BMC 1.5 feeding the glow plugs from the start terminal of the ignition switch is not a good idea because typically they need 20 or 30 seconds of pre-heat before cranking. I think that the wrong ignition switch has been fitted in the past.

 

You do not need a Lucas one, a Durite or any other four position switch will do, although you might have to change the cable terminals to suit.

 

Very few typical 9 diode alternators will self energise when running, so my confidence in your electricians advice is about zero. Basically alternators do not have much residual magnetism in the rotor (unlike dynamos), and as you need up to about 0.7V to "open" the diodes so current can be fed to the rotor. This means they simply do not self energise and need the warning lamp current through the rotor to get them to. LED or grain of wheat bulb warning lamps will not normally energise the alternator. Ensure your warning lamp blub is at least 1.5 watts, with 2.2 watts better, and up to 6 watts depending upon the actual warning lamp body. Some more modern boats put a resistor in parallel with the bulb to boost the current.

 

Occasionally you can get a 9 diode alterantor to self energise but usually only shortly after you stopped the engine only if you rev the engine to maximum.

 

25 minutes ago, Mike on Sea Hustler said:

Google and ChatGPT both tell me that (in layman’s terms) if the pre heaters draw too much power  away from the exciter circuit during the initial cranking phase my ARC17/18 may well not be able to self energise afterwards.

 

 I am tempted to respond with a word relating to dangly bits. Basically alternators do not energise while the starter is operating, but within a few seconds of returning the key to the run position, when the glow plugs and starter are no longer drawing power. That looks like yet another AI hallucination to me.

 

If that were true then the batter would have been too flat to crank the engine.

 

I will Google for a four position Durite switch when I get back from picking my wife up from church.

 

 

I see Pearely has beaten me to it.

 

Edited August 2 by Tony Brooks

[Mike on Sea Hustler]

Thank you guys, this has been an ongoing problem that seriously limits our use of the boat by requiring us to visit marinas almost every other day to hook up to shore power or risk running the batteries down. As an old motorsailer, we use her more as a motor than a sailer, the latter being more like trying to blow a house brick across the village pond with a drinking straw. It would be so much better if the damn batteries would charge as we puttered along rather than all this faffing about with charging. Here’s hoping I have finally zeroed in on the cause 

[MtB]

1 hour ago, Mike on Sea Hustler said:

Good Morning all,

 

So the charging issues continue. As some may recall I have issues with the charging aboard Sea Hustler. Despite extensive work to try and sort the problem, it continues. Thus far the charging system has been rewired and separated from the domestic electricals so basically the alternator is connected directly to the starter battery with all new cables and avoids the torturous route it previously had through the electrical panel. This produced a charge but only at higher revs than I was happy running the engine and only on the single occasion after the installation was completed, - thoughts here of fitting the smaller alternator pulley which I have in stock.  Next time running the engine, nothing, not even at increased engine speed. Removed alternator to check connections and upon installation it charged perfectly putting out over 14v while I ran for an hour down to my local fuel berth. Stopped the engine to refuel and upon restarting, nothing, and nothing since. Removed alternator and replaced brushes, regulator and rectifier still nothing. Tried tensioning the belt to eliminate any possibility of slippage, nothing works. So turned my attention to the only remaining component that has thus far not been investigated fully- the ignition switch. Examination reveals that it is a Lucas 128AS, apparently common in BMC installations of the time and what was to be expected in a boat built in 1968. However, and it seems daft to say it now but while looking into this, I realised that despite it being a Lucas 128AS, it only has three positions, instead of the usual four, 1.off, 2 aux/run and 3. Start. My auto electrician did tell me that the pre heaters were energising during the cranking phase, but stupidly we did not make the connection. All the symptoms point toward the exciter circuit. He tells me that this should Not be an issue because the alternator should self excite once it is running BUT I THINK HE IS WRONG (even the experts can get it wrong sometimes) Google and ChatGPT both tell me that (in layman’s terms) if the pre heaters draw too much power  away from the exciter circuit during the initial cranking phase my ARC17/18 may well not be able to self energise afterwards. All this brings Me to the conclusion that I need to swap out this ignition switch. And this is a very lengthy way of bringing me to the question. I have looked at countless sites to find a suitable switch including Calcut Boats and they vary from cheap rubbish at £5.00 through to others at £70. I don’t want to gut a new switch that looks the part but simply stores up

problems for the future. Can someone tell me where I can get a genuine replacement that I can fit that will allow me to feel confident that at least i

have eliminate that component from the list of possible causes. I do not want to fit relays, diodes or tins of baked beans.

just a simple four position diesel engine ignition switch but one that will handle the power and not give me problems down the line. 
 

phew all that for one simple question. But at least I think i have explained the entire problem as we know it 

 

 

I can't help but worry you are just 'parts-swapping' without really diagnosing the fault. This is often unsuccessful. 

 

Far better to study and get to understand how an alternator works, then you can start testing the various voltages and currents to see which are wrong or missing. And one or more MUST be wrong, or it would all work! 

 

I also find the terminology in your post frustratingly vague. E.g. "This produced a charge but only at higher revs than I was happy running the engine and only on the single occasion after the installation was completed". I'd far rather read something like "On initial testing the ammeter on the control panel showed a charge current of 30 Amps at 1500rpm. On subsequent engine runs zero charge current showed, whatever the engine revs". Then we'd have a much clearer understanding of what happened, and how you knew!

 

And "Stopped the engine to refuel and upon restarting, nothing, and nothing since. Removed alternator and replaced brushes, regulator and rectifier still nothing." Presumably zero charge current you mean? Is that correct? And how are you measuring it? 

 

More constructively, I suspect there is no current in the excitation circuit to the alternator. I'd start diagnosing this by working out which terminal on the alternator carries the excitation current, then start the engine and use a clamp meter to directly measure the actual excitation current rather than trying to derive it from other information. If there is no current then it may well be the ignition switch at fault but if there IS current, then replacing the ignition switch will make no difference and be one more disappointment. Its always best to positively trace the fault. Then fix it rather than take guesses and hope. 

 

Note: I am not a boat electrician. 

 

 

 

[Tony Brooks]

11 minutes ago, MtB said:

 

 

I can't help but worry you are just 'parts-swapping' without really diagnosing the fault. This is often unsuccessful. 

 

Far better to study and get to understand how an alternator works, then you can start testing the various voltages and currents to see which are wrong or missing. And one or more MUST be wrong, or it would all work! 

 

I also find the terminology in your post frustratingly vague. E.g. "This produced a charge but only at higher revs than I was happy running the engine and only on the single occasion after the installation was completed". I'd far rather read something like "On initial testing the ammeter on the control panel showed a charge current of 30 Amps at 1500rpm. On subsequent engine runs zero charge current showed, whatever the engine revs". Then we'd have a much clearer understanding of what happened, and how you knew!

 

And "Stopped the engine to refuel and upon restarting, nothing, and nothing since. Removed alternator and replaced brushes, regulator and rectifier still nothing." Presumably zero charge current you mean? Is that correct? And how are you measuring it? 

 

More constructively, I suspect there is no current in the excitation circuit to the alternator. I'd start diagnosing this by working out which terminal on the alternator carries the excitation current, then start the engine and use a clamp meter to directly measure the actual excitation current rather than trying to derive it from other information. If there is no current then it may well be the ignition switch at fault but if there IS current, then replacing the ignition switch will make no difference and be one more disappointment. Its always best to positively trace the fault. Then fix it rather than take guesses and hope. 

 

Note: I am not a boat electrician. 

 

 

I totally agree, and I think the OP has had the alternator off and tested as serviceable. If so then that screams a boat fault on the energisation circuit.

 

Normally when the main charging cable goes to the instrument panel it is because the boat has a cheap and nasty moving iron ammeter, and as the OP has rewired the main circuit I wonder if he has isolated the ammeter so it won't show a charge even if the alternator is working, but the odd time it does not suggest this may not be the case, but we really need a charging circuit diagram, including the feed to the ignition switch and warning lamp.

 

I have never heard of an 17/18 ARC, so am fairly sure it is an ACR. The energisation terminal (D+) is the small 6mm blade that sits, together with a pair of 10mm ones, inside the stepped rectangular cutout in the plastic end cover. The cables running to these terminals normally sit inside a plastic moulding so manually energising the alternator is not so easy because getting access to the 6mm blade involves pulling the plug out and that also pulls out the main charging cable(s). 

 

I think it is time to take the terminals out of that block and make sure they are clean and tight when pushed onto their respective alternator terminal. Also ensure the conductors are still clean and firmly attached to the terminals. If they look OK I would pull the 6mm (D+) terminal off and do two things.

 

1. With ignition on touch the terminal to something metal or battery negative - the bulb should come one. If not work back to the earning lamp looking for a broken wire/loose connection.

 

2. Clip a length of cable onto the main starter terminal and then with the engine revving at (say) 1200 rpm touch the other end to the 6mm blade for a few seconds. That should energise the alternator. If it does not then either the alternator is faulty or there is a problem with the main output wiring to battery.

 

However, the ACR range has been obsolete for many years and an A127 is normally a simple direct replacement, and the OP could get a 70 amp one.

 

 

 

34 minutes ago, MtB said:

I'd start diagnosing this by working out which terminal on the alternator carries the excitation current, then start the engine and use a clamp meter to directly measure the actual excitation current rather than trying to derive it from other information. If there is no current then it may well be the ignition switch at fault but if there IS current, then replacing the ignition switch will make no difference and be one more disappointment.

 

My take on this is that assuming the ignition warning lamp is connected to energise the alternator then if the switch was faulty the ignition light would never come on or be very dim. I am not sure a clamp meter would reliably measure the very small current in the warning lamp circuit. Especially as at the alternator end it will probably also be touching the main charging cable(s).

 

@Mike on Sea Hustler is your charge slit between two battery banks, and if so, how is this done? If it is a 1, 2, both, off switch try it set to both and report back.  Also, if it is a two battery bank boat, please confirm the engine and domestic battery bank negatives are connected together. 

[MtB]

1 hour ago, Tony Brooks said:

My take on this is that assuming the ignition warning lamp is connected to energise the alternator then if the switch was faulty the ignition light would never come on or be very dim.

 

I never like to assume anything at all when fault-tracing. It just creates/leaves an area of doubt. Best to either make certain or better, take it out of the equation totally which is why I suggested a clamp meter to measure the excitation current. Or even better, a proper ammeter inserted in series with the 6mm spade connection you described.

 

 

1 hour ago, Tony Brooks said:

I am not sure a clamp meter would reliably measure the very small current in the warning lamp circuit.

 

Nor am I sure on an ACR alternator, but on my 24V Leece-Neville alternator it was almost 3 Amps. Easily detected with a clamp meter provided you get the clamp jaws fully closed around the single correct lead. I saw someone recently confidently use a clamp meter around a whole bunch of cables including the one we needed to measure the current in, and the jaws not even fully closed. They saw nothing wrong with this! Odd how people's understanding can be so flaky!

 

 

[Tony Brooks]

14 minutes ago, MtB said:

I never like to assume anything at all when fault-tracing. It just creates/leaves an area of doubt. Best to either make certain or better, take it out of the equation totally which is why I suggested a clamp meter to measure the excitation current. Or even better, a proper ammeter inserted in series with the 6mm spade connection you described.

 

 

That is why I prefaced my reply with the assume bit. I have known boats where the red light that comes on when the ignition is turned on was nothing more than an ignition on light, but that would not go out when charging, and it certainly would not energise the alternator. Hence, saying we need the charging circuit diagram as it is now. There are also questions related to charge splitting with diodes and 1,2, both, off switches, and how they relate to the energisation circuit.

 

TBH, I am beginning to think that the only way to solve this is a visit to Portsmouth. I wonder if @Sir Nibble is still in the area and how much he charges for "house calls".

 

I would not take Leece Nevile readings to be representative of Lucas kit, although they may be (no practical experience). From memory the rotor has a resistance of around 3 ohms but the warning lamp is in series with it so that increases the resistance of the warning lamp circuit.

[Mike on Sea Hustler]

Honestly guys, I really do appreciate all the responses I receive but please remember, I am a novice at this stuff, I do my best to follow what people more knowledgeable then myself suggest but I don't always get it right and I may not describe things in the correct manner for which I apologize. I hate electric work because I can't see whats happening, water, yes, if it leaks I can see it pouring out of a split hose, apart from sticking my fingers into an electrical socket, I have no clue if that is working or that is live, what volts or amps,  or ohms or AC DC BC or X is going on, heck I've had a multi meter for over two years and I'm only just beginning to understand how to use it. The joys of being neurodivergent as I am, cover many fields, that includes anything not tactile such as electricity, in particular marine and auto electrics where AC is DC and BC is upside down and CD is something you play music on, all of which  I find difficult to visualize at the same time struggling to understand what many of you explain to me.

 

I don't think I'm simply part swapping, I have (I Think) systematically tried to eliminate possible causes from the wiring, alternator, connections and batteries one by one and now believe I have arrived at the doorstep of Mr and Mrs Ignition switch. I carried out a number of tests under the guidance of ChatGPT (I know; but when you haven't got a clue yourself and you're hanging upside down in the engine bay next to a ton of hot spinning stuff contorting yourself into shapes you did not believe possible just to get a probe on to a particular contact, all the while being rolled about by the wake of a passing ferry) believe you me ChatGPT is a very helpful, if maybe not perfect tool. However, as a consequence of my electrical acrobatics, ChatGPT did report that all the tests it advised me to try, 9.5mm blades, 6.3 mm, black probe on the casing, red probe in your ear, both with the engine running and not,  all returned expected numbers apart from a couple across the slip rings and something else I cant remember,  none of which I could do without once more removing the alternator and opening it up again, something I was not prepared to do 4 hours away from my home port.

 

I think I have understood the basics, but accept that I may not have, in order for the alternator to charge, the exciter circuit needs to energize and this it gets via or from - I don't know which/how/why, the ignition light. If this exciter circuit is not getting that current -voltage - amps or whatever, no amount of spinning whizzing or turning will get that alternator to produce a charge. Three of the common faults that can prevent any alternator from working are the brushes, regulator and rectifier which is why I swapped them out to eliminate that possibility - not just random part swapping. The wiring has been simplified and rerouted away from the panel to reduce the possibility of there being a fault somewhere in there. The entire charging system has essentially been replace and isolated from anything that went before apart from the ignition switch and ignition lamp, both of which I am now attempting to replace.

 

I now understand that my current three position switch, even though is is stamped Lucas 128AS has for some strange reason either  lost or never had a forth position to it. Hence I only have 1.Off 2. Aux/run and 3. Start, during this spring loaded start phase, it has been determined that the pre heaters are energized, something I have learnt is not incorrect, what I lack it would seem is any position 3,  PRE heat provision which should continue into the 4th position cranking phase but immediately turn off as soon as the key returns to the run position.  I am informed that the draw from the pre heaters MAY drain enough power/amps/volts/sausages, whatever away from the exciter circuit so much so that the exciter circuit fails (for want of a better word) to do its job and kick start the charging from the alternator _which I understand is necessary because ACR 17/18 alternators do not carry a permanent magnetic filed which must be produced by the wiggly thingy bobbly bit in order for the charging process to begin.

 

IF and I accept its a big IF, the fault lays within the exciter circuit, and the problem there is within the missing position three/ faulty switch internals/ a spell cast by the wicked witch of the sparky world, swapping the switch out and connecting the correct cables to the appropriate terminals should/could/maybe

/please God make it work, solve the problem. 

 

I hope you will all understand that I value your input immensely, but hope you will also understand that what may seem straightforward and obvious to you, is a minefield of uncertainty to me,  please don't criticize me for not explaining things in a manner that is common place to you, or misunderstanding this or that, we all have skills, mine are not boat electrics.

 

Don't mean to offend but I've been struggling with this issue for the past three years and in truth I'm just looking for easy answers now.

[Tony Brooks]

48 minutes ago, Mike on Sea Hustler said:

now understand that my current three position switch, even though is is stamped Lucas 128AS has for some strange reason either  lost or never had a forth position to it. Hence I only have 1.Off 2. Aux/run and 3. Start, during this spring loaded start phase, it has been determined that the pre heaters are energized, something I have learnt is not incorrect, what I lack it would seem is any position 3,  PRE heat provision which should continue into the 4th position cranking phase but immediately turn off as soon as the key returns to the run position.

 

But for a 1.5 it IS incorrect. They are called pre-heaters for a reason, you use then pre (before) the starter.

 

48 minutes ago, Mike on Sea Hustler said:

I am informed that the draw from the pre heaters MAY drain enough power/amps/volts/sausages, whatever away from the exciter circuit so much so that the exciter circuit fails (for want of a better word) to do its job and kick start the charging from the alternator _which I understand is necessary because ACR 17/18 alternators do not carry a permanent magnetic filed which must be produced by the wiggly thingy bobbly bit in order for the charging process to begin.

 

I consider that I am now wasting my time trying to help. You admitted you got this information from AI and probably Google did as well. 

 

The exciter circuit can only do its job once the engine is running and possibly with some revs on it. Under those conditions the starter (which draws over 100 amps) and the glow plugs that on a BMC 1.5 with the original pattern glow plugs draw roughly a steady 25 amps, but they will all be off almost a soon as the engine starts, so they simply can't affect the energisation. 

 

If the battery was flat enough for the glow plugs to discharge it enough to stop the alternator energising then the battery would not have enough charge to operate the starter. 

 

Even if the cable feeding the ignition switch was sufficiently undersized for the glow plugs to cause sufficient volt drop to stop energisation, it would also pull the voltage down enough to stop the starter solenoid operating, but that is immaterial because neither the starter nor glow plugs will be working (energised) during alternator energisation because the ignition switch will have been released for start and it would jump back to just the ignition on position.

 

It maybe better for all if we left you to AI to try to help you sort this. We need a diagram, not your assertions as to how the charging circuit is wired.

 

One last attempt to help you solve this.

 

The ACR series had a surge quench diode bolted to the end bracket with a wire running to a small blade that is part of the diode pack heat sink. If that fails short circuit the alternator will not energise. Diodes can fail in funny ways, sometimes intermittent. It is a domed thing about 8 mm in dimeter that has a flat mounting plate with a single mounting bolt in it. If you have one (under the black plastic cover) try disconnecting the lead, I think it tended to be yellow and don't confuse it with the leads from the regulator. If you have got those mixed up it also may not energise.

 

Item 36 on this image

 

 

 

 

Are you aware that a short circuit to negative on the cable between the warning lamp and alternator D+ would cause the warning lamp to work as if there was no charge, but would not allow the alternator to energise.

Edited August 2 by Tony Brooks

[MtB]

1 hour ago, Mike on Sea Hustler said:

I don't think I'm simply part swapping, I have (I Think) systematically tried to eliminate possible causes from the wiring, alternator, connections and batteries one by one and now believe I have arrived at the doorstep of Mr and Mrs Ignition switch.

 

I think you're still not quite getting it. And ChatGPT certainly isn't. Components are only one of three (or more) separate arenas in which a fault can exist. You might have faults in any or all of the following arenas:

 

1) Components

2) Wiring faults, cable connections in particular

3) Circuit design

 

ChatGPT only seems to be considering 1). If you do the test I suggested then you'll either have a 100% rock solid diagnosis. You will know with 100% certainty whether missing excitation is the fault, or if it isn't the fault. Then can rule out (or in) the whole subject of excitation.

 

And if you don't get how to do it (I already explained), then your task is to ask questions about how, learn, do it and get the result. Its no more difficult than water plumbing, in fact there a LOT of parallels. Voltage for example is equivalent to the water pressure behind a closed tap. Amps (or current) is equivalent to water flow rate, i.e. how many buckets a minute of water is coming out of the tap when you turn it ON.  And both of these can be measured using the right instruments.

 

You said you've had someone else working on this, which worries me. Diagnosing this fault should be easy and I bet Tony would pin it down within five minutes of sitting down and unpacking his toolbox in front of this engine. And so should your electrician except he hasn't. In my experience when someone who doesn't actually know their stuff starts messing with something they more often than not inadvertently introduce more faults. I fear this could have happened to your system.

 

 

Edited August 2 by MtB
Spelling and grammar

[Tony Brooks]

7 minutes ago, MtB said:

You said you've had someone else working on this, which worries me. Diagnosing this fault should be easy and I bet Tony would pin it down within five minutes of unpacking with toolbox in front of this engine. And so should your electrician except he hasn't. In my experience when someone who doesn't know their stuff starts messing with an installation they more often than not inadvertently introduce more faults. I fear this could have happened to your system.

 

It worries me as well, especially as the OP as reported some advice from him that I find highly suspect. I also fear that much of this rewiring will need careful checking so diagnosing it could take hours. It all needs tracing, then working out what it is supposed to do and how, and finally testing to work out why its is not. 

 

Frankly, I find being told that I am wrong because AI & Google said so is rather insulting unless my questions are answered and proof given as to why I am wrong. I bet you get the same re boilers and their controls, especially if the customer has been taking advice from another "professional" who can't diagnose or fix the problem. It seems 65 years plus experience, much practically on the tools, counts for nothing when AI is consulted.

[Bod]

In view of all the bits already done, I would want to know if the alternator in it's current form has been bench tested to confirm it does actually work as it should.

 

Bod

PS

I have seen an alternator rotor that tested perfectly when static, powered up there was a definite fault.

It was thought to be a broken wire, when static made a connection, but at speed the centrifugal force created a gap between the broken ends.  

Edited August 2 by Bod

[jonathanA]

I would suggest you just get back to basics. The KISS principle is needed - keep it simple ...

 

If t was me I would strip out, or at least disconnect all the existing wiring from the ignition  switch, charge warning lamp and alternator.  Leave the starter wiring as that's working. Either leave the heater plugs disconnected or fit a temp switch if they are needed.

 

All you need is a wire from the on/aux terminal to the charge warning lamp then from the other connector on that to small spade terminal on the alternator thats the "exciter" as you are terming it. Then a reasonably beefy wire or wires from the big spade terminals to the battery positive. Either direct to the battery or more likely just use the starter motor battery connection. 

 

Basically that's all you need. Switch on the ignition, charge light comes on. Start engine, charge light goes out (maybe a blip of throttle needed) and your charging. If the charge light doesn't come on then you need to investigate further, if it doesn't go out then you need to investigate that further.   You just need a bit of wire say 4 or 6mm2 for the alt to battery positive,  anything for the ignition switch to warning light to alternator D+.  Plus a few 6.3 and 9mm female crimp connectors 

 

This is just a basic circuit to test the components once it's all proven then it can be done properly. But at least this removes any extraneous bits that might or might not be working or correctly wired. 

 

Anyway that's what I would do to eliminate all the confusion/ambiguity etc... 

[Mike on Sea Hustler]

BThank you guys, this has been an ongoing problem that seriously limits our use of the boat by requiring us to visit marinas almost every other day to hook up to shore power or risk running the batteries down. As an old motorsailer, we use her more as a motor than a sailer, the latter being more like trying to blow a house brick across the village pond with a drinking straw. It would be so much better if the damn batteries would charge as we puttered along rather than all this faffing about with charging. Here’s hoping I have finally zeroed in on the cause 

Oh dear, try looking up neurodivergent guys. You all jump on your huffy high horses and basically shout at the dumb idiot that doesn’t think like you. Don’t worry, you won’t have to try and demonstrate your superiority again, I’ll not bother returning to this forum in the future. Disappointed 

Edited August 2 by Mike on Sea Hustler

[Llamedos]

I think I understand but I wouldn’t take it too personally.
 

Some of these guys are very good engineers but aren’t always the most gentle in the way they explain stuff. It often gets a bit intense on here. If it’s any consolation the discussion lost me at an early stage. 
 

Might be worth just re reading the thread quietly later on - the answer may well be in there somewhere. If not, there’s nothing to lose.

 

I really do hope you get it sorted soon it sounds really frustrating. 

[MtB]

I can't see any reply by either myself or Tony which was anything other than courteous. 

 

Stating you are neurodivergent makes no difference to how to trace and fix it. We have both tried to explain how to fix this problem to our best ability. That's all we can do. I simply don't understand what the OP wants us to do if not explain in the simplest terms we can, which he seems to have totally ignored. Or not acknowledged at best. 

 

 

[Jen-in-Wellies]

There is often a disconnect on here. Some people want to solve a techical problem. They understand from bitter personal experience, gained over years, that having all the facts is important and that if the root cause is taking a long time to find, 9 times out of 10, it will be something you have already dismissed as it couldn't possibly be that. Genuine problem solving is a constant attack on your own ego and sense of competence. Hence the questions. Hence the pushing on something that the other person has already dismissed.  It looks obsessional, but only if you don't realise that problem solving requires that level of detail.

 

Other people want their ego massaged, while they try and solve the problem. They don't understand why people are going on about something they have already dismissed. They don't understand the logic behind eliminating all possible causes, rather than replacing each part in turn, from the most expensive first. They consider the questions as an attack on them, even after they have said they don't know what is going on. Hence the reactions and flouncing out we see here again and again. 

 

The CWDF experts here are giving years of hard won experience for free. You could pay a fortune for help of this calibre at a boat yard and consider it money well spent and recommend them to other boaters. The difference is that here, they are asking you to do the detailed checking and measuring required that they would do, on account of you being on the boat and them not being able to see it.

[Alan de Enfield]

This seems to be an intermittent problem.

 

Whenever I get an intermittent electrical problem I initially start looking for loose connections/joints and/or a bad earth connection.

Follow every cable in the circuit or put in temporary 'jumpers' from A-B and see if the problem goes away

 

Once all of the circuit (potential) problems are removed you can go onto looking for component failures.

[MtB]

2 hours ago, Alan de Enfield said:

This seems to be an intermittent problem.

 

Whenever I get an intermittent electrical problem I initially start looking for loose connections/joints and/or a bad earth connection.

Follow every cable in the circuit or put in temporary 'jumpers' from A-B and see if the problem goes away

 

Once all of the circuit (potential) problems are removed you can go onto looking for component failures.

 

The OP doesn't accept this and is getting annoyed by people constantly suggesting this.

 

They want it to be a component that needs replacing, so that is what they are doing. I think they want people to agree with them, not come up with helpful suggestions about why it might not be an individual component failure. 

 

 

[Jonah]

Mike, if by any chance you are still reading, just take a breath and re- consider.

As a newbie on here and previously a lurker, I have seen both sides of this type of scenario many times, and being disconnected, can see both sides.

Without trying to sound patronising, I understand your situation and frustration completely, and sometimes what's in your head, negates what's being said.

Because I don't understand electrics completely, for my own benefit I have read and re-read all of the suggestions from the very helpful members, and mostly they then make sense (to me)

With this in mind, may I make a suggestion ?  Tell the guys you are going to re-read areas that don't make sense to you, and come back later/tomorrow, so they don't feel 'let down' by a sudden exit, or flounce, as the pi$$takers  that sometimes jump in and refer to, and you get no further response.

Quietly re-reading and going over with eyes on if you are on board, can make a difference.

Frustrating as it is for you, it can be the same for those members freely giving expert advice.

Remember, its all been serious suggestions/advice, from knowledgeable people in their field, with no pi$$taking from anyone, and I'm sure you will get to the bottom of your problem with the help given. Good luck.

Jonah.

[ditchcrawler]

6 hours ago, MtB said:

 

The OP doesn't accept this and is getting annoyed by people constantly suggesting this.

 

They want it to be a component that needs replacing, so that is what they are doing. I think they want people to agree with them, not come up with helpful suggestions about why it might not be an individual component failure. 

 

 

But that is how they do modern fault finding, change the bit you think is faulty and when that doesn't work change another bit

[Jen-in-Wellies]

2 minutes ago, ditchcrawler said:

But that is how they do modern fault finding, change the bit you think is faulty and when that doesn't work change another bit

The most expensive bit first, then by order of part cost, for a truly modern approach. 

[Peanut]

8 minutes ago, ditchcrawler said:

But that is how they do modern fault finding, change the bit you think is faulty and when that doesn't work change another bit

Yes, that's how Mercedes do it. Plug it in, read the fault code, replace the component, repeat, until there are no more fault

codes.

Rebuilding the car at Mercedes prices.

Edited August 3 by Peanut
add a bit.

[Tony Brooks]

1 minute ago, Jen-in-Wellies said:

The most expensive bit first, then by order of part cost, for a truly modern approach. 

 

For vehicles often the bit the computer says has failed while totally failing to grasp that the computer only knows the parameter it is receiving is incorrect, which could be a broken wire, loose connection or a bad earth. A bit like the AI says XYZ in this topic so anyone trying to get some diagnosis going must be wrong.