Solenoid problem...

[Janz]

Afternoon boaters!

Took my boat out for a jaunt yesterday. Been having a few problems which I thought were battery/alternator related but I took my starter battery home & gave it a good charge & the problem is still evident.the engine won't turn over. It wants to but it's cranking really slowly & my batteries are fully charged.

Each time I try & start it, a small plume of smoke rises from the solenoid connections. I have taken it off & cleaned it up but I think I need a new part. Damn! Lucas, Prince of Darkness is peeing on my parade...

[MtB]

Ah yes, the Price of Darkness can be high when Lucas is involved...

[Tony Brooks]

This assumes that your battery switch is set to start battery and the start battery is well charged and not faulty..

 

As you know how to solder and presumably de-solder many solenoids can have their plastic cap taken off and the contact bar and contacts inspected and cleaned. Just make sure that when you put it back the twin thin solenoid wires are soldered back into the small terminal (bald) that energies the relay.  First check that the smoking terminal is clean and tight. Also make sure all the heavy negative cable connections are clean and tight.

[springy]

Let a multimeter be your friend, measure the voltage between the solenoid to battery connection and starter body (should be battery voltage), both at rest and while cranking. also the starter input connection and starter body while cranking, also (for reference) the voltage across the battery terminals. This should hopefully pinpoint the problem, or at least indicate where to test next (isolator switch ?). You could also measure the voltage drop (while cranking) across the main solenoid terminals - holding the probes on both the studs first, and then on the cable terminals to check for poor connections. These measurements should only show as small or ideally zero volt drop.

 

springy 

[Janz]

1 hour ago, Tony Brooks said:

This assumes that your battery switch is set to start battery and the start battery is well charged and not faulty..

 

As you know how to solder and presumably de-solder many solenoids can have their plastic cap taken off and the contact bar and contacts inspected and cleaned. Just make sure that when you put it back the twin thin solenoid wires are soldered back into the small terminal (bald) that energies the relay.  First check that the smoking terminal is clean and tight. Also make sure all the heavy negative cable connections are clean and tight.

Thanks Tony. I've been right through the charging system & it's good. All batteries are green for good & putting out over 13v. I've tried to dismantle the solenoid in situ but I can't desolder the terminals with my puny iron. So I did what I could & now it's blowing the 30 amp ignition fuse behind the key switch. Not good! I'm 99% sure it's the solenoid. I'm just going to get a decent second hand or aftermarket part & bung it on. I'm quite far from where I usually plot up & I'm busy tomorrow but I'll keep you guys in the loop as to progress. On the plus side, I've tidied up all the wiring to eliminate a short circuit occurring somewhere else & causing hassle at the solenoid. All the battery connections have been cleaned with steel wool. They were corroded & bodged. I fitted two new positive terminal clamps to the leisure batteries & one for the starter battery & cleaned up around the whole bay. The crimp spade terminals are awful & coming apart. They're the cheap Wilko ones. My brother has lent me a few quid so I'll buy some good ones & systematically renew them everywhere. Another plus is the isolator switch. The markings are unreadable but I've worked out what's what with that. It's slow progress but at least it's progress.

It going to be a busy week...

[Janz]

57 minutes ago, springy said:

Let a multimeter be your friend, measure the voltage between the solenoid to battery connection and starter body (should be battery voltage), both at rest and while cranking. also the starter input connection and starter body while cranking, also (for reference) the voltage across the battery terminals. This should hopefully pinpoint the problem, or at least indicate where to test next (isolator switch ?). You could also measure the voltage drop (while cranking) across the main solenoid terminals - holding the probes on both the studs first, and then on the cable terminals to check for poor connections. These measurements should only show as small or ideally zero volt drop.

 

springy 

Thanks Springy.

My pal has my meter. I won't be seeing him this week but I think there's a massive voltage drop when cranking...

I'll see if I can borrow one...👍

[Janz]

3 hours ago, MtB said:

Ah yes, the Price of Darkness can be high when Lucas is involved...

You're not wrong. What happened to all the millions of starter motors in the millions of cars from BL? Surely they all didn't end up in China being recycled. There's not a lot out there second hand. If I recall my Austin/Morris/MG experiences the starter motors were never great. I'd have to leave my Mini at the top of Underhill Road in East Dulwich most nights in winter, coast down & bump it.

My solenoid is a 77034. Searching for that brings up a lot of far east clones but nothing Lucas. Anyone know what cars they were fitted to? Think the MGB GT had them, some old taxis too but there surely must be some classic car dude sitting on a few tons of BMC spares somewhere, but where? Years ago there was a guy south of Croydon called BL Transverse. He used to do all manner of British car stuff. He can't be still there, he was ancient when I was a kid...

[Troyboy]

The days of visiting a scrap yard for BMC 1.5 diesel spares are long gone I'm afraid . The engine was fitted to J2 and J4 vans and the Morris Oxford and Austin A60 . It was also fitted in some Nuffield /Leyland tractors . From searching on Ebay it would appear that your solenoid was also fitted to some Land Rovers and Perkins engines . Sadly I think you are going to have to fork out £26 and get a Lucas copy made in China /India or somewhere other than the UK. 

[Tracy D'arth]

The biggest killer of starter motors is trying to start with a flat battery.

Because the motor can't get up to speed due the battery being below par, it draws more current than normal which overheats the windings causing burning and failure.

[Tony Brooks]

Also if just one of the brushes in a pair does not make good contact the motor will not spin up to speed so the same applies. I get the impression its an old engine so  maybe the OP should take the end cover/band off the motor to inspect the brushes.

 

I hope the phrase "green for good" refers to a hydrometer reading rather than the "magic eye", if it is the eye the OP has been mislead. He would do well to tell us the battery cranking voltage in case he has a faulty cell.

[Janz]

44 minutes ago, Troyboy said:

The days of visiting a scrap yard for BMC 1.5 diesel spares are long gone I'm afraid . The engine was fitted to J2 and J4 vans and the Morris Oxford and Austin A60 . It was also fitted in some Nuffield /Leyland tractors . From searching on Ebay it would appear that your solenoid was also fitted to some Land Rovers and Perkins engines . Sadly I think you are going to have to fork out £26 and get a Lucas copy made in China /India or somewhere other than the UK. 

Cool, well I'm not a big fan of far eastern stuff but if I have to get one of those, I will... & fix mine whilst it's off the engine. Thanks for the heads up on which vehicles that part was fitted to. I'll try & see if I can get one. Someone will have one, it's just a matter of time 'til I find one...👍

[Tracy D'arth]

No problem finding solenoids. But check the motor first. Cargo website lists them all.

[Janz]

1 hour ago, Tracy D'arth said:

The biggest killer of starter motors is trying to start with a flat battery.

Because the motor can't get up to speed due the battery being below par, it draws more current than normal which overheats the windings causing burning and failure.

Well I did have to bridge the solenoid to get it started the other day. So the problem is definitely not the batteries. They all charged up & hold their charge pretty well considering my boat hasn't really been in the water since 2012, aside from when the people who sold it to me craned it in & out to test it for leaks before welding. I have no clue as to the history of the batteries, whether they were taken from another boat but they're far from new. The electrics are by far the worst part of the boat - the water pump needed work, the shower pump needed work, you've seen the quality of the electrical 'workmanship' from the photo of the fuse box. It's all like that. I gave it all a good tidy up today, so at least I can move around in the bay now. All the wiring has gone hard & uses crimped on connectors. Now I know that's how boats are done 'cos I got told but it doesn't make for reliable connections. I have already been chastised for wanting motorbike bullet connections & soldered joints, so we won't go there... I'm going to have a couple of days off to reflect & charge my own human batteries 'cos I've been at this for a month now & I need a break. I've moved a couple of miles from where I was plotted up so I've fulfilled my CRT obligations. I'll find an old tractor solenoid from somewhere...👍

13 minutes ago, Tracy D'arth said:

No problem finding solenoids. But check the motor first. Cargo website lists them all.

Thanks for that, I'll have a look.

[Janz]

47 minutes ago, Tony Brooks said:

Also if just one of the brushes in a pair does not make good contact the motor will not spin up to speed so the same applies. I get the impression its an old engine so  maybe the OP should take the end cover/band off the motor to inspect the brushes.

 

I hope the phrase "green for good" refers to a hydrometer reading rather than the "magic eye", if it is the eye the OP has been mislead. He would do well to tell us the battery cranking voltage in case he has a faulty cell.

13.4 - 13.8. The batts are good. The magic eye, loool... I'm busy tomorrow. I need to drive to the Welsh valleys & back & the day after I'm going to rest up. But I won't be idle. Going to take down the rest of the wood panels in the hallway but I can't get them to the boat where it is because it's a long walk from the road. I'm going to measure out the cabin & work out how long to make them into the equal lengths needed to cover the walls & ceiling so I can then place batons over the jointed bits where they screw into the woodwork. It may be like living in the inside of a big beer barrel but I don't mind that. The main problem I can foresee is where the bodywork swoops inward as you get towards the bow...

[Tony Brooks]

2 minutes ago, Janz said:

13.4 - 13.8. The batts are good. The magic eye, loool... I'm busy tomorrow. I need to drive to the Welsh valleys & back & the day after I'm going to rest up. But I won't be idle. Going to take down the rest of the wood panels in the hallway but I can't get them to the boat where it is because it's a long walk from the road. I'm going to measure out the cabin & work out how long to make them into the equal lengths needed to cover the walls & ceiling so I can then place batons over the jointed bits where they screw into the woodwork. It may be like living in the inside of a big beer barrel but I don't mind that. The main problem I can foresee is where the bodywork swoops inward as you get towards the bow...

 

That is not the cranking voltage, it is not even the rested voltage. It is the charging voltage from an older alternator, the charging voltage with fairly discharged batteries or the voltage before the surface charge has dissipated. It means nothing. I had a battery with two faulty cells that would give that sort of reading soon after being charged, a couple of hours later it was down to around 8 volts and the next day much lower. I am not saying the start battery is faulty but  am saying that you have not given any information to prove that it is not faulty.

 

If you have batteries with the magic eye in the top then it only monitors one cell so is useless for diagnostic purposes.

[Janz]

Well they'll have to do, Tony. They work alright & I can't afford new ones. Despite me having had to remove all my solar panels for those two storms we had, they remain at over twelve volts. One panel is still missing. It blew clean off the boat but I intend to find that. I just want to get the starting system running. The charging system is ok too. The solenoid is the only thing that smokes, it's forty years old & has had a hard life being partly open to the elements. I have a canopy but that was a new addition by the former owner. For £26 I think I'll be alright with a new solenoid. 

[Tony Brooks]

1 hour ago, Janz said:

Well they'll have to do, Tony. They work alright & I can't afford new ones. Despite me having had to remove all my solar panels for those two storms we had, they remain at over twelve volts. One panel is still missing. It blew clean off the boat but I intend to find that. I just want to get the starting system running. The charging system is ok too. The solenoid is the only thing that smokes, it's forty years old & has had a hard life being partly open to the elements. I have a canopy but that was a new addition by the former owner. For £26 I think I'll be alright with a new solenoid. 

 

The fact you can't afford new batteries  does not mean the old ones work OK. maybe they did before you flattened them, With solar charging them during daylight they may have started the engine, but that does not mean they are not faulty in some way now. "They work all right" is nothing more than an assertion you are making because you can't back it up with any meaningful data.

 

Once again. What is the cranking voltage, and please no more assertions. The cranking voltage will give a very good indication of battery condition. However I don't think  care any more.

[john.k]

Always have a direct earth cable from starter to battery terminal.........earthing through the motor can reduce the voltage enough to slow the starter...........and of course a direct cable from the other battery terminal to the starter............Smoke often means either looseness of the terminal bolts ,or corrosion on the connections.............solder can be a trap too,if a terminal gets hot ,solder runs out and frees the connection......a proper crimp with a tool is better,

[Mikexx]

17 hours ago, Tracy D'arth said:

The biggest killer of starter motors is trying to start with a flat battery.

Because the motor can't get up to speed due the battery being below par, it draws more current than normal which overheats the windings causing burning and failure.

 

Are you sure about this? Torque is strongly dependent on current, so less torque at any speed will mean less current. For the BMC motors I have come across there two parallel circuits, where each comprised of field and armature in series. Because both field and armature fields are dependent on current, if it wasn't for saturation of the magnetic materials torque would be a square function of current. I would be more worried about killing the battery.

 

I have known a starter on a Sherpa draw lots of current and not provide enough torque. It was diagnosed by a minimal drop at the battery and the expected voltage drop to the motor, but would smoke after a prolonged attempt to start. A replacement solved the problem.

 

For the OP, a meter is the only way to determine faulty solenoids, switches, crimps and starter motor. One with a DC clamp meter would be ideal, but most troubleshooting is from measuring volts.

[Tony Brooks]

I would suggest the bit about fault finding by measuring volts should include knowing how to conduct voltage measurement to ensure the result is accurate. This OP has already posted voltage readings that in now way helped diagnose the problem and shows he has yet to understand what he is trying to measure.

 

Yes that is correct. By and large the slower most brushed DC motors run the more current they draw and in the case of a typical starter motor at zero revs the resistance is not far off zero ohms. That is why electric motors develop maximum torque at zero  speed. What limits the current in a running electric motor is the inductance caused by the fluctuating magnetic fields in the motor producing a "back emf (voltage)" so that in effect the voltage able to push current through the motor is reduced so less current flows and the torque is reduced.

 

Hence maximum  current and maximum torque at zero revs when there are no pulsating magnetic fields.

[john.k]

Starter may be poling out due to bearing wear....or maybe its full of brush dust with worn out brushes and grooved commutator.

[Tony Brooks]

45 minutes ago, john.k said:

Starter may be poling out due to bearing wear....or maybe its full of brush dust with worn out brushes and grooved commutator.

 

That is why I have already suggested that he take the end cover or body band off the motor so he can have  a look. He could well be trying to start with only half the motor working because of bush wear on one brush pair. However he seemed reluctant to take the starter motor off so he could deal with his solenoid cap so I doubt he will do this either.

 

 

I just hope is motor is not one that requires the pinion throw to be  adjusted when a new solenoid is fitted.

 

 

[MtB]

6 hours ago, Mikexx said:

One with a DC clamp meter would be ideal,

 

 

The OP has declared (IIRC) that he is opposed to buying specialist tools because they are, well, specialist. 

 

No it makes no sense to me either, unless I misunderstood. 

 

 

 

 

[Tony Brooks]

27 minutes ago, MtB said:

 

 

The OP has declared (IIRC) that he is opposed to buying specialist tools because they are, well, specialist. 

 

No it makes no sense to me either, unless I misunderstood.

 

 

That is how I understand it and it seem that he would rather spend money on random new or better still secondhand parts than try to do a proper diagnostic job to find out what he really needs. Makes no sense to me either but each to their own.

[StephenA]

6 hours ago, Tony Brooks said:

 

That is why I have already suggested that he take the end cover or body band off the motor so he can have  a look. He could well be trying to start with only half the motor working because of bush wear on one brush pair. However he seemed reluctant to take the starter motor off so he could deal with his solenoid cap so I doubt he will do this either.

 

 

I just hope is motor is not one that requires the pinion throw to be  adjusted when a new solenoid is fitted.

 

 

 

Dropping the starter motor on a BMC 1.5 isn't the hardest thing to do. It can be a bit of a pain if you are attempting it single handed but it's possible, and once it's out it's so much easier to check things.