smoking battery w124

[christokane]

Good morning peeps , I hope you can help me.
After a short drive to work (5k) , I left the car running for few mins then popped across to a garage for a coffee... just as I pulled in I noticed the SRS light come on then the car cut out.. and I noticed smoke coming from the battery corner of engine bay.. I opened the bonnet and nothing was on fire just smoke from the battery and now it won't start.
Any ideas please? Thanks

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[carat 3.6]

Possible OVP relay fault.

 

[Sp!ke]

It is likely to be the over voltage protection relay as already suggested but it could also be something as basic as low battery acid in one or more cells which could lead to buckled plates and require a battery replacement.

 

[Martyn_n]

Is it a Boeing / Yuasa battery?

 

[teddycatkin]

Good morning peeps , I hope you can help me.
After a short drive to work (5k) , I left the car running for few mins then popped across to a garage for a coffee... just as I pulled in I noticed the SRS light come on then the car cut out.. and I noticed smoke coming from the battery corner of engine bay.. I opened the bonnet and nothing was on fire just smoke from the battery and now it won't start.
Any ideas please? Thanks

Sent from my Sony Arc S using MBClub UK

1st check loose terminal or wires -low or no acid in battery?

 

[christokane]

I'm not sure what battery it is , it's still across the way at the garage.. but it did have an acid type smell from the smoke... seemed very sudden for a battery fail no?

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[tonywashere]

Is it a Boeing / Yuasa battery?

Ground it immediately

 

[grober]

It might be an alternator regulator pack failure leading to over charging of the battery which is almost certainly now "toast" as the Americans so graphically put it.

 

[christokane]

Firstly it's a Varta battery...
I've just been reading up on it and it says the OVP is linked to the idle speed also... my idle has been rough lately when cold. Maybe it WAS on it's way out.

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[christokane]

Found the problem... it's the wiring loom just at the OVP relay...
Now gotta decide to tackle it myself or not...

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[RBYCC]

Hopefully only the OVP wiring...

 

[christokane]

Well I'm guessing the relay is gone too but I have one there now.. just wondering what will be more successful , to insulate each intricate wire or make a fresh cut and replace the relay connection with one in better condition

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[RBYCC]

Do the "fresh cut"....use what you know is a connector in good condition which will limit the chance of a returning problem.

 

[christokane]

And use a block connector???

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[Mercedes man]

Hi could be regulator on alternator over charghing battery

 

[christokane]

So my loom is nearly completely melted... this could be pricey :-(

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[carat 3.6]

So my loom is nearly completely melted... this could be pricey :-(

Sent from my Sony Arc S using MBClub UK

Send Billy a pm, he may be able to help: http://www.mbclub.co.uk/forums/members/billyw124.html

 

[christokane]

thanks, will do... he has a spare loom you think?

 

[RBYCC]

Prior to installing and powering up the replacement loom, locate the cause of the problem. Possibly it was the loom itself breaking down with age or a loose connection that created a high resistance and heat that broke down the insulation.
Inspect the old OVP to see if it had an internal short.

 

[kth286]

I've seen the loom that goes across rear of engine to MAF melt due to heat
and shorting of the MAF wires resulted in rough running.

Perhaps it's that.

You can undo the MAF plug (at the MAF) and check for shorted wires with the ECU plug also disconnected.