Strange starter problem

[cauchoiskev]

Here are the symptoms : off the car, all works fine. On the car, a click then nothing. The engine is not seized. I've checked the wiring by shorting it out, no difference. The battery seems fine, 12.9V, headlamps work, hardly dim when trying to start.

With the ignition on "start", I get only 0.5V on the starter when it's on the car. A jump lead direct from the starter terminal (by-passing the solenoid) to the battery makes it whirr normally.

So I think the problem is with the solenoid, but then why does it work off the car ? I use the same battery.

My current hypothesis is that the fork does not travel quite as far when it is on the car (for reasons I can't explain) , and contact is not being made correctly. You do have to push the plunger completely in to get the switch to work.

I have put a drop of araldite on the end of the plunger to lengthen it by about a mm, I'm waiting for it to harden. Unfortunately, the solenoid (Valeo) does not seem to be non-destructively openable to check the contacts.

Any other ideas would be welcome, as I don't have great confidence in my bodge working...

[DavidRutherford]

Have you tried a jump cable between the battery +ve and the normal start connection on the solenoid with the starter in the car? It sounds to me like your starter feed in the car isn't very healthy.

To dismantle the solenoid you do need to un-solder the connections to the solenoid windings. Bit of a pain, but it should come apart.

[cauchoiskev]

Have you tried a jump cable between the battery +ve and the normal start connection on the solenoid with the starter in the car?

Yes, I've tried that David, it made no difference, all I got was I click. I think all the wiring is OK.

As for opening the solenoid, the end of the casing is folded inwards, and I think it will be necessary to grind the lip off in order to get the plastic cap out. That will probably be my next step if the araldite bodge doesn't work.

[BXrunner]

try tapping the solenoid with a hammer then try starting the car is it manual or auto too sometimes the inhibitor switch will quit on auto

[DavidRutherford]

try tapping the solenoid with a hammer then try starting the car

Given that the motor works on the bench, how will that help?

sometimes the inhibitor switch will quit on auto

Again, cauchoiskev has mentioned that the solenoid clicks, but doesn't do anything more, so that statement is irrelevant.


It's certainly a bizzare problem, but does sound like the solenoid contacts are burned, or possibly the solenoid travel is being limited by something. I suspect you'll find that there's corrosion or something similar in the solenoid should you pull it to bits.

[citroen7]

i had a similar problem on my estate it would click and click and i would put it in top and rock it and eventually it would start . so i did the same took it out and it worked fine. i then took it too the chap up the road and it turned out that the starter motor was misalliened so instead of engaging the flywheel it was jamming on it a couple of washers and a bit of jiggery pokery and it still works to this day

[cauchoiskev]

That is interesting, but in my case when the solenoid just clicks I am not getting full voltage to the starter (only about 0.5V). If it was jamming, I think I would still get 12V on the output of the solenoid.

I'm fairly sure that it is a dodgy solenoid. At the moment it works most of the time, but it will surely fail completely at some point. I am sorely tempted to open it, but that will mean the whole thing, solenoid and starter, will be valueless if I don't manage to fix it.

[CitroXim]

That is so often how these starters fail

205GTi starters fail regularly just like this and in their case it is blamed on heat. Where they live they run a bit warm.

I've tried stripping and cleaning them but it's only a temporary respite.

Nothing more annoying than an intermittent starter. Dig in your pocket and buy a recon one. Expensive I know but worth it on a dark and stormy night...

[AlanS]

My guess is worn carbon brushes as they give all the symptoms of the solenoid being caput.
Standard procedure in these cases is to firstly fit a solenoid to the starter circuit, if you want to be 100% certain, then fit a separate starter button so as to take all the load off the ignition switch, then replace the brushes.
You'll find with the BX that the solenoid is a sealed unit and can't be readily dismantled and that the new carbon brushes, or more correctly the springs that hold them in are modified to prevent a recurrence and the relay should prevent the voltage drop all that common to these systems.

http://www.aussiefrogs.com/forum/showth ... rter+motor


Done a few now and all have worked 100% and a few others have also found it to be the answer to this problem.
You'll be amazed at how fast and instantly it works after this.


Alan S

[jeremy]

Has the switch failed? Leave the battery connection (large wire) in place and take the switch contact off and jump it from the battery.

[cauchoiskev]

@AlanS

The brushes were my first thought, I foolishly ordered them from the local motor factor, then opened the starter. The brushes looked fine, but there was un unbelievable amount of filth inside the casing, which looked like a mixture of dog hair and dog poo - how the hell did that get in ? Aha, I thought, the problem was the dirt. But of course it wasn't.

@Jeremy

I have already jumped all the contacts, it makes no difference, there is still intermittent failure. So yes, I think the switch is at fault.

I am starting to envisage a starter switch on the dash to do the job of the solenoid switch, as I'm damned if I'm going to throw away a perfectly good starter motor. The problem will be to find -or make - one capable of withstanding 400A. Either that or a very heavy-duty relay....


The problem we've found with the brushes is that with the original springs behind them, they tend to push harder on one side than the other. As a result, the operating face gets angled and this coupled to voltage drop from the ignition switch to solenoid causing the lazy connection in the solenoid, can create a situation where one brush can be sitting across 2 segments on the commutator whereas the other is raised on one side, hence ho circuit.
As has been said by others; a direct connection to the motor won't work due to the double operations the pinion performs.
\

Alan S

[jeremy]

The solenoid does 2 things -

Firstly it moves the pinion into mesh with the flywheel teeth when the motor is operated and withdraws the pinion when the engine starts.

Secondly it switches the heavy starter current on when the motor is in mesh.

A starter button will simply replace the key switch starter contacts and operate the solenoid as before.

The old type of inertia starter did not have the solenoid mounted parallel with the motor and engaging with the gear. It simply relied on the rapid acceleration of the motor to force a gearwheel along the motor shaft and into mesh with the flywheel. The solenoid on these was simply a heavy duty electrically operated switch - and on some vehicles - earlier Minis, petrol Land Rovers to 67, vans etc simply had a plain switch with a large push button on it.

[cauchoiskev]

A starter button will simply replace the key switch starter contacts and operate the solenoid as before.

My idea of a starter button was directly to the starter motor, bypassing the solenoid switch i.e. the full whack of 300-400Amps. Turn the key as usual, wait for the click, then hit the button. Do you see what I mean ?

As it happens, my araldite on the tip of the plunger bodge has actually worked, somewhat to my surprise. That should give me enough time to find a heavy duty switch or relay to replace the duff solenoid contacts. One of those old Mini/landy switches you mention sounds like just the job !

[DavidRutherford]

My idea of a starter button was directly to the starter motor, bypassing the solenoid switch i.e. the full whack of 300-400Amps. Turn the key as usual, wait for the click, then hit the button. Do you see what I mean ?

All that will do is make the starter motor spin. It won't do the other function of the solenoid, which is to pre-engage the starter pinion with the flywheel.

I'd be looking for a second-hand starter from a breakers yard. Usually they're very reliable, so most of the ones from breakers will be fine.

[jeremy]

The point is that if you use a heavy switch connected to the big terminal on the starter it will spin beautifully and make a nice noise - but as it won't have been put in mesh with the engine it'll be as much use as a chocolate teapot.

The function of the solenoid is to put the pinion in mesh then turn on the heavy current to the motor.