Smoking..

PostPost by: Robbie693 » Tue Nov 25, 2008 2:15 pm

..the car that is.

My Plus 2 is suffering from lack of use :cry: . I went to give it a run today but it didn't want to go out in the cold (flat battery).

Whilst attempting to get it to fire with it's last remaining energy I noticed smoke coming from the starter solenoid (this is after 5 mins of rur,rur,rur). Is this just a symptom of me trying to flog a dead battery or do I have some kind of high resistance somewhere?

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PostPost by: Alex » Tue Nov 25, 2008 4:05 pm

Hi Robbie,

I suspect you might have damaged the contacts in your starter solenoid. They are only really designed to take starter current for short bursts when starting a car. 5 minutes of cranking is very likely to have over heated the contacts. It may still work fine for years but I would imagine the current carrying capacity of the contacts will have been reduced resulting in lower current getting to the starter.

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PostPost by: Robbie693 » Tue Nov 25, 2008 4:10 pm

Hmm, maybe that's why, when I came back with jump leads, it was still turning over very slowly..

I'll try it again when I've charged up the battery but it may be worth getting a new solenoid anyway as they're cheap (I think).

Thanks Alex

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PostPost by: Lincoln62 » Tue Nov 25, 2008 11:08 pm

I once burned out the starter on my Escort trying to start it after hit some water and stalled.

I was told by my Auto electrician that when trying to start a difficult car, 10 seconds cranking then 20 seconds rest for the starter to cool down will stop your starter from frying and allow your battery time to recover before the next burst.

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PostPost by: greg.harvey » Tue Nov 25, 2008 11:25 pm

Indeed. I never have to crank for more than about 10 seconds, twice, before I get a spark of life - and it only takes that long if she's sat for 3 or 4 weeks. If I went out the weekend before, she'll fire in 5 seconds, no problem. She won't start for another few attempts, but you know she's going to. In my experience an old Elan ought to have at least coughed after 20 seconds of cranking or you probably have bigger problems. :(

In my case usual suspects are blocked accelerator jets (it'll still go but takes twice as long to fire and won't pull away smoothly unless you're really gentle on the throttle) and damp in the distributor. It's always been either one or the other or both!
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PostPost by: paddy » Tue Nov 25, 2008 11:44 pm

If the smoke is coming from the solenoid, it means that the resistance is there - and some resistance is inevitable - and not elsewhere in the circuit.

I'd try it again when cold before deciding that the solenoid itself is damaged. It's going to get hot, and any accumulated grime will burn off, but I would think it would need to get very hot indeed before the contacts are permanently damaged.

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PostPost by: neilsjuke » Wed Nov 26, 2008 12:36 am

Put a volt meter on the solenoid terminals if you get more than 1/2 a volt when cranking the terminals/solenoid are shot.
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PostPost by: andyelan » Wed Nov 26, 2008 8:06 am

Hi Robbie

Be careful trying to start a car with a low battery.

An electric motor will always try to generate enough torque to overcome whatever load is resisting it. If the battery supply voltage is low the only way it can do this is by drawing more current (amps). This can easily overheat and damage the motor winding and associated wiring.

It may seem odd, but you are more likly to burn out the starter when the battery voltage is low rather than when its in good condition.

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PostPost by: Robbie693 » Wed Nov 26, 2008 2:23 pm

Thanks for all the tips guys,

The car spun over fine this morning with a freshly charged battery so I assume the solenoid is ok. I will check with a voltmeter as Neil suggested when I get a minute.

Cheers

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PostPost by: billwill » Thu Nov 27, 2008 12:58 am

neilsjuke wrote:Put a volt meter on the solenoid terminals if you get more than 1/2 a volt when cranking the terminals/solenoid are shot.
neil


I take it that you mean the high current terminals feeding the starter motor?
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PostPost by: paddy » Thu Nov 27, 2008 8:04 am

Yes.

Before cranking the voltage across the two terminals will be 12V, and it will fall to zero, or near zero, when cranking. This is the voltage you should measure.

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