Smartgauge " stuck "' at 76

[RLWP]

The Lucas test card recommendation was to unplug/disconnect the wire in question and sue a voltmeter.

 

This No Win, No Fee culture is getting out of hand

 

Richard

[nicknorman]

Hi Nick,

Back at a big screen now, and spotted the OPs readings on the yellow and green wires to the back of the alternator.

These two wires are the same as the start battery alternator on your Beta, one is the warning light, the other is an ignition feed from the key switch. On yours they are probably labeled "I" and "L", and probably the same on the OPs. The green "I" wire has been variously described here as excite, permanent or sense; but whatever we call it will need to be live with the key switch on for the alternator to charge. The green wire is fed from the domestic battery bank by a relay controlled from the key switch. The OP has already taken readings at the relay indicating a lack of output, so a relay change is a "dirt cheap" and worthwhile thing to try.

The only small "fly in the ointment" is that there are two configurations for those small relays, absolutely identical in appearance, but with the terminal numbers in different place - standardisation, ho hum.

I would be seriously impressed if this Hitachi alternator is original, as they do seem to get a lot of "bad press". Could still be real benefit from having the alternator serviced regardless of outcome with the relay. Tony has already mentioned that they may not be repairable; so best to have it serviced to extend life before a failure renders it un repairable.

Steve (Eeyore)

Yes I think my description was over simplistic as it didn't mention the relay. However, unless I have misread the OP he says that when he puts the light bulb onto a terminal directly on the alternator, it brings the alternator warning light on the panel on. Therefore surely we must conclude that the relay is working correctly as is everything else in the circuit to the "excite" terminal, and the fault must lie internally with the alternator?

 

He also mentions that the wires from the alternator don't go far before there are some bullet connectors and the wires change colour. Surely a probable indicator that a different model of alternator with different electrical fittings, has been retrofitted?

 

Edit: right, I've had another think about what you said and sort of see your point I think. Regarding the 2 wires actually coming out of the alternator one was at 12v and when grounded, brings the warning light on. The other was at 0v and I presumed it was the W connection, however you are saying it is some sort of battery-sensing connection I think? And yes, I hadn't spotted that one would expect 3 out of 4 wires on the relay to be at 12v with the ignition on. What I am not sure of is the consequence of not having the remote battery sense lead connected via the relay.

 

In particular, what effect would it have on the excitation current? Surely even if there was something up with the remote sensing (relay) one would still expect the "excitation" terminal to take some current and thus bring the light on, and the fact that it is not still points to an alternator fault, or is that wrong?

Edited December 17, 2014 by nicknorman

[Eeyore]

Yes I think my description was over simplistic as it didn't mention the relay. However, unless I have misread the OP he says that when he puts the light bulb onto a terminal directly on the alternator, it brings the alternator warning light on the panel on. Therefore surely we must conclude that the relay is working correctly as is everything else in the circuit to the "excite" terminal, and the fault must lie internally with the alternator?

He also mentions that the wires from the alternator don't go far before there are some bullet connectors and the wires change colour. Surely a probable indicator that a different model of alternator with different electrical fittings, has been retrofitted?

Edit: right, I've had another think about what you said and sort of see your point I think. Regarding the 2 wires actually coming out of the alternator one was at 12v and when grounded, brings the warning light on. The other was at 0v and I presumed it was the W connection, however you are saying it is some sort of battery-sensing connection I think? And yes, I hadn't spotted that one would expect 3 out of 4 wires on the relay to be at 12v with the ignition on. What I am not sure of is the consequence of not having the remote battery sense lead connected via the relay.

In particular, what effect would it have on the excitation current? Surely even if there was something up with the remote sensing (relay) one would still expect the "excitation" terminal to take some current and thus bring the light on, and the fact that it is not still points to an alternator fault, or is that wrong?

Hi Nick

As far as I know the warning light connection on these alternators plays no part in excitation, and is just an electronic switch controlled by the regulator to turn the light on and off. So wouldn't expect much with just the warning light wire live via the warning light.

May I suggest tracing the green wire in the alternator plug back to a connection on the relay; it may or may not change colour on its way there. Remove the identified wire from the relay and extend it back to the domestic battery live (or the alternator thick red lead, whichever is easier). Turning on the ignition should illuminate the warning lamp and sound the buzzer. If it works as expected a change of relay should do the trick.

NB the Nippon Denso alternator on your Beta may have "I" and "L" on two spades configured in a tee shape, or as two of the terminals in the later ovoid 3 pin plug. Some engines I recall had a short adaptor to allow the 3 pin plug alternators to be used on harnesses with the tee shaped plugs.

Steve (Eeyore)

Edited December 17, 2014 by Eeyore

[nicknorman]

Hi Nick

As far as I know the warning light connection on these alternators plays no part in excitation, and is just an electronic switch controlled by the regulator to turn the light on and off. So wouldn't expect much with just the warning light wire live via the warning light.

May I suggest tracing the green wire in the alternator plug back to a connection on the relay; it may or may not change colour on its way there. Remove the identified wire from the relay and extend it back to the domestic battery live (or the alternator thick red lead, whichever is easier). Turning on the ignition should illuminate the warning lamp and sound the buzzer. If it works as expected a change of relay should do the trick.

NB the Nippon Denso alternator on your Beta may have "I" and "L" on two spades configured in a tee shape, or as two of the terminals in the later ovoid 3 pin plug. Some engines I recall had a short adaptor to allow the 3 pin plug alternators to be used on harnesses with the tee shaped plugs.

Steve (Eeyore)

Oh dear, well if that is true it seems I may have misled the OP. That is what comes of trying to apply general knowledge to a specific case. I wonder if he is reading??

I've sent him a PM:

 

Hi there, not sure if you have been reading your "Smartgauge stuck" thread this afternoon but Eeyore (Steve) has thrown up a critical point. He is not just a professional, but a professional who has a lot of experience and who is knowledgeable, helpful and intelligent and whose opinion I respect.

 

He thinks your alternator is a type whereby the warning light is not part of the "exciter" circuit but simply a circuit switched by the regulator to indicate alternator working or not. More importantly the other of the two wires going into the back of the alternator must be connected to battery +ve in order for the alternator to work. It is important that this is the battery to which the alternator relates, ie the domestic battery in this case. By contrast when you turn the ignition on, you turn on power from the engine battery. To overcome this, a relay is fitted (that black lump on the alternator tensioning bar) such that when engine battery power is applied, it closes the contacts on the relay so as to connect domestic battery +ve to the alternator. As he says, you would expect that the 4 wires in this relay would be, with the ignition on, 12v from the ignition switch to the relay coil, 0v from the relay coil to -ve, 12v from the domestic batteries, and 12v routing through the relay to the alternator. But you only had 2 at +12v which suggests the relay contacts haven't closed.

 

Therefore, sorry to say, but it is possible or even probable that the alternator is fine but it is the relay that is defective. A much easier fix. If you look at Steve's post he recommends connecting the wire on the back of the alternator that is at 0v, to the domestic battery +ve and then trying the engine to see if it now charges. If this is the problem you will need a new relay but note his comments about the connection pattern. Sorry if I have caused too much confusion, we both learn from these things.

Edited December 17, 2014 by nicknorman

[Eeyore]

Oh dear, well if that is true it seems I may have misled the OP. That is what comes of trying to apply general knowledge to a specific case. I wonder if he is reading??

I'll try a PM.

 

Shouldn't be a problem, as there is no harm in having the alternator checked anyway; and I have already advised to do that.

I always like to see the forum operate in a "mutual improvement" kind of way :-)

Knowing from other topics that you already had similar alternator wiring on your boat made it easy to explain.

That relay has a harsh life cable tied to some part of the engine. Sometimes it's just the spade terminals vibrated loose, but most likely the relay in this case.

Have a look at this page for the OP, it shows the two different mini relay formats, one is type A, and the other (although not labeled as such) is type B. It's pins 86 and 30 that are transposed.

http://www.durite.co.uk/pdf/2014/6/06.01_Relays_and_Flashers-Make_and_break_relays.pdf

Apologies to Chubby (only been referred to as the OP), I do it this way so that you only need to deal with one person, it's easier for you that way.

Steve (Eeyore)

Edited December 17, 2014 by Eeyore

[Eeyore]

Oh dear, well if that is true it seems I may have misled the OP. That is what comes of trying to apply general knowledge to a specific case. I wonder if he is reading??

I've sent him a PM:

 

Hi there, not sure if you have been reading your "Smartgauge stuck" thread this afternoon but Eeyore (Steve) has thrown up a critical point. He is not just a professional, but a professional who has a lot of experience and who is knowledgeable, helpful and intelligent and whose opinion I respect.[/

Most people say:

"Wow Steve you're so full of it that even your eyes are brown"

But I'm warming to your version ;-)

[nicknorman]

Don't take it too much to heart, if you were perfect you'd have been here yesterday morning!

Knowing from other topics that you already had similar alternator wiring on your boat made it easy to explain.

 

Trouble is, nothing has ever gone wrong with the charging on our boat so I have never had to look at it too closely! I note that on our boat, the engine alternator is battery-sensed whereas the (huge) domestic alternator is machine sensed. Doesn't seem to logical but I suppose that's just the way it is. Edited December 17, 2014 by nicknorman

[nicknorman]

Actually while you are on, please could you explain why the relay for the domestic alternator is required on my boat. The relay just connects the B+ on the alternator, via the warning light, to the D+. Surely the "machine sensing" is done from the B+ terminal so I don't really understand why having a slightly wrong voltage the other side of the warning light (ie connecting it direct to the ignition switch) with batteries at different states of charge would be a problem, other than causing the lamp to glimmer faintly in an extreme case?

[Eeyore]

Actually while you are on, please could you explain why the relay for the domestic alternator is required on my boat. The relay just connects the B+ on the alternator, via the warning light, to the D+. Surely the "machine sensing" is done from the B+ terminal so I don't really understand why having a slightly wrong voltage the other side of the warning light (ie connecting it direct to the ignition switch) with batteries at different states of charge would be a problem, other than causing the lamp to glimmer faintly in an extreme case?

Sorry Nick, that would be question for someone like Sir Nibble.

I've always taken it as best practice to ensure that all connections are made with regard to the battery bank that the alternator is charging.

An interesting aside to this is that sometimes the warning buzzer can make a slight "churpping" noise when the two battery banks are at very different states of charge.

Steve(Eeyore)

Edited December 17, 2014 by Eeyore

[Tony Brooks]

Actually while you are on, please could you explain why the relay for the domestic alternator is required on my boat. The relay just connects the B+ on the alternator, via the warning light, to the D+. Surely the "machine sensing" is done from the B+ terminal so I don't really understand why having a slightly wrong voltage the other side of the warning light (ie connecting it direct to the ignition switch) with batteries at different states of charge would be a problem, other than causing the lamp to glimmer faintly in an extreme case

 

On machine sensed alternators the sensing is done via 3 (usually) smaller diodes in effect on the D+ terminal s there may very well be a small difference in voltage between B+ and D+. This is why a field diode failure can result in excess charging voltage.

 

I think the relay on your boat is only there to work the domestic alternator's warning lamp and thus excite it. To be honest I can not see why you could not have another warning lamp feed from the ignition switch but I suspect the relay may be used used (depending upon where it is fed from) to save needing an extra cable in the main wiring harness. In that way single alternator engines do not have to have the cost of that extra cable and the same harness can be used to single and twin alternator boats apart from the extra domestic alternator B+ and B- cables. I suspect the relay is energised from the other alternator's D+

[nicknorman]

On machine sensed alternators the sensing is done via 3 (usually) smaller diodes in effect on the D+ terminal s there may very well be a small difference in voltage between B+ and D+. This is why a field diode failure can result in excess charging voltage.

 

I think the relay on your boat is only there to work the domestic alternator's warning lamp and thus excite it. To be honest I can not see why you could not have another warning lamp feed from the ignition switch but I suspect the relay may be used used (depending upon where it is fed from) to save needing an extra cable in the main wiring harness. In that way single alternator engines do not have to have the cost of that extra cable and the same harness can be used to single and twin alternator boats apart from the extra domestic alternator B+ and B- cables. I suspect the relay is energised from the other alternator's D+

Regarding the field diodes to D+ as you say I would have thought connecting a bulb to a slightly different voltage wouldn't have much impact, but maybe it does. But the use of the relay adds another cable to the loom (the relay is in the instrument panel) - it needs a wire from the panel to D+ of course, but also another wire from the panel to that alternator's B+. These two wires are on a separate 2way connector so obviously an afterthought. Whereas there is already another wire from the other alternator's B+ that runs all the engine systems. The relay is definitely energised from the other alternator's B+ (aka engine battery +ve) not the D+. If it were the latter, the domestic alternator warning would not come on with the ignition switch, and a failure of the engine alternator could prevent the domestic alternator from working.

 

I do note there is provision in the wiring loom for Beta's alternator controller that is no longer used, so maybe the relay and powering the domestic alternator's D+ from its B+ is a hang up from that.

[smileypete]

Actually while you are on, please could you explain why the relay for the domestic alternator is required on my boat. The relay just connects the B+ on the alternator, via the warning light, to the D+. Surely the "machine sensing" is done from the B+ terminal so I don't really understand why having a slightly wrong voltage the other side of the warning light (ie connecting it direct to the ignition switch) with batteries at different states of charge would be a problem, other than causing the lamp to glimmer faintly in an extreme case?

 

Might be that with D+ fed from the other batt, there's a risk that starting the engine with a batt iso open will energise the alt with no output connected. ISTR there may be some other reason though...

 

cheers, Pete.

~smpt~

[nicknorman]

Might be that with D+ fed from the other batt, there's a risk that starting the engine with a batt iso open will energise the alt with no output connected. ISTR there may be some other reason though...

 

cheers, Pete.

~smpt~

Yes that scenario would be prevented (putting aside for a moment that our boat was built with the domestic alternator connected to the battery side of the domestic isolator) but is it actually bad to power up an alternator when not connected to a load? As opposed to disconnecting the load when the alternator is in full flight - which is definitely bad or fatal for it. With the travel power on and Combi charging set to a slightly higher voltage than the alternator, the alternator's output is zero when the batteries are well charged and so is that any different to having no load connected at startup? Edited December 17, 2014 by nicknorman

[chubby]

Good evening ,

 

Apologies for my lack of replies . I ve been catching up on some studies as i ve had divert my knackered brain to my latest boat problem!!

Firstly ,

Thankyou all for your help & advice . 99.9999 % has gone over my head but im a dunce . For all in know you may have talking about the inner working of R2 D2 !!! But its all good stuff , so thankyou .

 

The alternator has been pronounced knackered on arrival . The auto electrician says that the relacement parts were £92 & £18 . Or a new one £130 . Same model so it should be simple to reconnect to the existing wiring & grey plastic harness .

The new may arrive tomorrow or maybe Friday & i ll get a call when it arrives . If it turns out that it doesn t work once fitted then i shall swear loudly ... just once , have a cup of tea , calm down & consider myself to now have a new alternator & a spare & crack on with trying to solve the problem .

 

If i suppose the worst & the new alternator doesn t work because fault is elsewhere are there any parts or equipment i ought to source in advance so i can get on with the job asap . Im off to my folks on Saturday , returning 23rd & hoping to be cruising on xmas eve . No worries if i cannot but i don t fancy trying to buy auto electrical bits n bobs on xmas eve .

 

Again - thanks for all the help & advice .

 

Its only a narrowboat ... whys it all so complicated !!???

 

cheers

[RLWP]

im a dunce

 

Yeah - right. Such a dunce that you have used the forum to seek advice, followed through some complicated tests and diagnosed a duff alternator. Excellent work, Mr C

 

I've learned quite a bit in this thread, thanks guys

 

Richard

[nicknorman]

I've learned quite a bit in this thread, thanks guys

 

Richard

Me too! One of which is that it is dangerous to extrapolate from your own installation to someone else's. But then we both knew that already! But in the end it seems I got away with it!

[Tony Brooks]

Regarding the field diodes to D+ as you say I would have thought connecting a bulb to a slightly different voltage wouldn't have much impact, but maybe it does. But the use of the relay adds another cable to the loom (the relay is in the instrument panel) - it needs a wire from the panel to D+ of course, but also another wire from the panel to that alternator's B+. These two wires are on a separate 2way connector so obviously an afterthought. Whereas there is already another wire from the other alternator's B+ that runs all the engine systems. The relay is definitely energised from the other alternator's B+ (aka engine battery +ve) not the D+. If it were the latter, the domestic alternator warning would not come on with the ignition switch, and a failure of the engine alternator could prevent the domestic alternator from working.

 

I do note there is provision in the wiring loom for Beta's alternator controller that is no longer used, so maybe the relay and powering the domestic alternator's D+ from its B+ is a hang up from that.

 

 

The B+ wire is almost certainly the feed to one side of the relay contacts. It certainly is not the energising wire because if it were the relay would be energised all the time. I think is is energised from the other alternator's D+ terminal. Unless the master switch is turned off the B+ terminal will be at battery voltage all the time.

 

I think the engine warning lamp (plus any parallel resistors) probably passes enough current to energise the relay and excite the engine alternator but you have the boat to check on.

[nicknorman]

Good evening ,

Apologies for my lack of replies . I ve been catching up on some studies as i ve had divert my knackered brain to my latest boat problem!!

Firstly ,

Thankyou all for your help & advice . 99.9999 % has gone over my head but im a dunce . For all in know you may have talking about the inner working of R2 D2 !!! But its all good stuff , so thankyou .

The alternator has been pronounced knackered on arrival . The auto electrician says that the relacement parts were £92 & £18 . Or a new one £130 . Same model so it should be simple to reconnect to the existing wiring & grey plastic harness .

The new may arrive tomorrow or maybe Friday & i ll get a call when it arrives . If it turns out that it doesn t work once fitted then i shall swear loudly ... just once , have a cup of tea , calm down & consider myself to now have a new alternator & a spare & crack on with trying to solve the problem .

If i suppose the worst & the new alternator doesn t work because fault is elsewhere are there any parts or equipment i ought to source in advance so i can get on with the job asap . Im off to my folks on Saturday , returning 23rd & hoping to be cruising on xmas eve . No worries if i cannot but i don t fancy trying to buy auto electrical bits n bobs on xmas eve .

Again - thanks for all the help & advice .

Its only a narrowboat ... whys it all so complicated !!???

cheers

Oh well so at least I didn't give you a bum steer on the alternator being faulty. If I may suggest it, I suppose it is possible you mis-measured the voltages at the relay. Even if you didn't and the relay is duff, you can temporarily connect a wire between the green alternator wire, and the fat red one. This will "turn on the alternator" if it as Steve describes. You would have to have the wire in situ all the time the engine is running, and then disconnect it after you shut the engine down so as to avoid the battery draining. A nuisance, but a possibility in the short term.

[by'eck]

FWIW I have both alternators on my boat excited by common feed from starter battery but via individual warning lights. I was a little concerned when first installed, but there have been no issues in 1000 hours of use.

[nicknorman]

The B+ wire is almost certainly the feed to one side of the relay contacts. It certainly is not the energising wire because if it were the relay would be energised all the time. I think is is energised from the other alternator's D+ terminal. Unless the master switch is turned off the B+ terminal will be at battery voltage all the time.

 

I think the engine warning lamp (plus any parallel resistors) probably passes enough current to energise the relay and excite the engine alternator but you have the boat to check on.

Sorry I wasn't explicit enough, the relay is energised from the engine alternator's B+ (aka engine battery +) via the ignition switch. As I said, it couldn't be from the D+ as otherwise the domestic alternator light wouldn't illuminate when the ignition was turned on. This is confirmed by the wiring diagram, the relay is just another service off the ignition switch like the other warning lights and gauges.

[chubby]

Thanks again guys .

 

Nick , I must confess that one of my first thoughts when reading thru some the above stuff was

" i do hope i measured those 4 wires ( in what i now understand to be a relay switch ..... i think ) correctly "

 

I don t do myself any favours really . I m not a dunce , i just struggle with the theory of this kind of stuff . To me its like a science almost with a series of " laws " that underpin everything . Sometimes i can t get my head around it .

But i am patient , i am determined , i am organised , & able to follow instructions even if i don t entirely understand why . When someone knows more than me , i listen & try to learn & i ve learn t alot from this & try to do this with each & every problem i get on my boat ( many ) & turn , if possible , a negative situation into a positive one .

Hopefully the new one will solve the problems .

Thankyou again

[Eeyore]

Good evening ,

Apologies for my lack of replies . I ve been catching up on some studies as i ve had divert my knackered brain to my latest boat problem!!

Firstly ,

Thankyou all for your help & advice . 99.9999 % has gone over my head but im a dunce . For all in know you may have talking about the inner working of R2 D2 !!! But its all good stuff , so thankyou .

The alternator has been pronounced knackered on arrival . The auto electrician says that the relacement parts were £92 & £18 . Or a new one £130 . Same model so it should be simple to reconnect to the existing wiring & grey plastic harness .

The new may arrive tomorrow or maybe Friday & i ll get a call when it arrives . If it turns out that it doesn t work once fitted then i shall swear loudly ... just once , have a cup of tea , calm down & consider myself to now have a new alternator & a spare & crack on with trying to solve the problem .

If i suppose the worst & the new alternator doesn t work because fault is elsewhere are there any parts or equipment i ought to source in advance so i can get on with the job asap . Im off to my folks on Saturday , returning 23rd & hoping to be cruising on xmas eve . No worries if i cannot but i don t fancy trying to buy auto electrical bits n bobs on xmas eve .

Again - thanks for all the help & advice .

Its only a narrowboat ... whys it all so complicated !!???

cheers

Hi Chubby

Your hard work and Nicks guidance has produced evidence that the relay (black block with 4 wires) is faulty; and should be changed whilst the alternator is off (makes access easier)

I'm not particularly surprised at the auto electricians diagnosis, it's not uncommon for a piece of kit to retain some functionality with one fault, and then fail completely when another fault occurs. Certainly makes overall diagnosis more interesting.

Take a look at my link to the Durite website, your relay type will be either the 2nd or 5th diagram from the top.

Make a copy of either of those two diagrams, but leave the numbers off to start with. Identify each terminal on the drawing by the colour of the wire attached to the corresponding terminal on the old relay. Remove the wires and (having noted which way around it is mounted) remove the old relay. Using a magnifying glass read the terminal numbers off the old relay and mark the diagram accordingly. Purchase and fit a new relay of the correct type, cable tie it to the engine the same way around as the original; the wiring will now fit back exactly as it appeared on the old relay. Job done.

Steve (Eeyore)

1st Edit - sorry that took so long to post, called away for my supper half way though typing :-)

2ndEdit - your relay may have an unused 5th terminal marked 87a. This is a change over relay being used as a make and break relay, they are interchangeable in this application. Most electricians will carry type A and type B of the 5 terminal version as they work in place of a 4 terminal version - saves a bit of space in the spares box!

Edited December 17, 2014 by Eeyore

[chubby]

Cheers again ,

 

Proves the old saying about not counting ones chickens etc .

I m expecting a call later today , or tomorrow to say the replacement alternator has arrived .

 

Do you think the auto electrician would have these relay boxes in his workshop as a bit of bog standard kit ?

 

I ve got to go to my parents on saturday & unless i can get this replacement relay iff a shelf then i m likely to be stuffed , as i live on the boat & my postal address is rhat of my parents ....many miles away !

 

Im going to be back at the boat at about 3 pm . I will have to check the relay , & check your link & order one asap & hopefully they deliver by monday !!

 

Essentially you are saying that its the relay thats gone ? But the wirings ok ? This is proven by the voltmeter lamp coming on during testing ?

 

Thanks again for all the help on this - im extremely grateful .

 

I ll post back here on the progress as i go

 

 

cheers

[RLWP]

It seems unlikely that the alternator and the relay box have gone. Do the alternator and see what happens

 

Richard

[chubby]

Cheers

 

that is what i think i m to do .Im certain i tested correctly , but i wouldn t put it past me to have put the multimeter probe into the black box / relay & not made a contact .

Having said that i did try several times & only 2 of 4 wires showed a voltage.

 

I just check the link to the Durite website . The black box strapped to the alternator framework looks nothing at all like these .

 

The 4 wires have no spade connectors etc . They simply go into one. side of the black box . Then at the back of the box are exposed metal corresponding to where the wires go in on the oppsite side .

This coonector is not cube shaped , its more the shape like a domino or a match box .

 

The narrowboat learning curve steepens ......

 

cheers again

Edited December 18, 2014 by chubby