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aclwalker

Sudden loss of all electrical power.

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Had an interesting problem today. 50 yards into my journey, my VR6 lost all power, came to a halt and within a few seconds the dash display went totally blank. I'm pretty sure I saw a flash of light from under the bonnet and there was an electrical smoke smell briefly.

 

I was stuck at an angle on the main road, and after getting help to move it out the way, I started investigating. The battery was showing zero volts on my multi-meter!

 

The battery is 11 years old now. Having taken it out of the car, it seems to have recovered a bit to 8 volts, which is obviously still no use.

 

I'm worried that there's some sort of short somewhere, but the wiring all looks good. I recently replaced the starter, so I'm hoping that this hasn't shorted itself somehow.

 

Is it possible for batteries to short internally? Anybody got any idea what's happened here? It's a pretty spectacular end to my battery. I'm just worried that if I put a new one in that another fault I've not identified could kill the brand new battery.

 

Any advice appreciated...

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Thanks for that. Any idea where the main earth is on a VR6? Somewhere near the gearbox/starter maybe?

 

Overnight my battery has recovered to 10.5 volts, which would suggest one cell is dead. I'm going to try and get a battery today, but I'd like to check this earth anyway as I've never done this before.

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Got a new Bosch Silver S5004 (075 size) for £59.98 from Costco. A lot of the online battery places said the S5005 (027 size) was for the Corrado, but the Bosch catalogue in Costco said that the S5005 was for the Golf VR6 and S5004 for the Corrado VR6. I guess this is a common mistake.

 

To be honest, I think either would do. The only differences seem to be that the S5004 is 61Ah whereas the S5005 is 63Ah, and the S5005 is 1.5cm taller.

 

I'll be checking the earth strap tonight and hopefully be back on the road shortly.

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Well, tried to fit a new battery, and got massive sparks again with no ignition or anything on. I've checked the wiring as much as I can (in the dark, without taking anything apart) and it all seems fine. I saw a wisp of smoke coming from near the starter motor, so it's looking like maybe it has an internal short.

 

Could a dodgy ignition barrel cause this? I've been having a bit of difficulty recently with the key not turning the barrel easily, but I assumed it was just because the key is worn.

 

The starter is a refurb, only fitted 2 or 3 months ago. It's not as good as the old one was (occasionally fails to start), but I accidentally snapped the terminal off the old one.

 

Anyone heard of an internal starter/solenoid short?

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I can't help with any of the electrical info, but i do have a mk3 vr6 breaker which should still have the starter on it, which your welcome to if it'll come off ok?

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Thanks for the offer. I think I'll need to take the starter back though. It's only 2 months old.

 

It's not too difficult to get the starter off, but there are bolts and things in the way that can be a challenge. Also, you need to support the engine as you remove it as one of the bolts goes through the front engine mount.

 

Is it a manual transmission Golf Mk III? (Automatic uses a different starter I believe.) What year?

 

I'm beginning to think that the positive lead from the battery is maybe touching the case of the solenoid. I noticed that the terminal at the starter end is a square with a hole in it, rather than the usual circular. I guess it's possible that this has rotated when I've tightened it up and is touching against the sort of divider post between the two terminals. I wouldn't have thought that this was earthed, but maybe it is.

 

I've got some continuity testing to do tonight to try and diagnose the problem, but I think ultimately I'll need to get the starter out again, which I'm not looking forward to, on the public road (although in the side-street now), in winter, in Glasgow, in the week before Christmas!

 

The good news is that my old battery, even at 11 years old, has recovered admirably. I've only had it on charge for about 3 hours now (don't trust it enough to charge in my flat while sleeping or out!) and it's approaching working voltage, having been totally flattened in a fraction of a second.

 

It will at least do as an ECU-saver battery when replacing other batteries!

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Well, finally got a break in the weather today, so disconnected the alternator and reconnected the battery without sparks. I was able to start the car fine and it ran normally. I didn't run it for long though as it's not a good idea with the alternator disconnected. As soon as I reconnected the alternator, car not running, the sparks and smoke started again, so it looks like my 3 month old alternator has shorted itself. I've checked all the wiring, and taped parts of it where I thought it could possibly have shorted but it still does.

 

Anybody heard of this before?

 

I suppose the good news is that there doesn't appear to be too much damage apart from the alternator wiring which clearly can't cope with the current draw.

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To complete this thread, it was the alternator that failed. Only 3 months old (rebuild) and completely shorted via the case. Continuity between the +ve post and the case. It dumped the whole contents of my battery in a few seconds. I'm struggling to find a replacement now.

 

Edit: plea for spare working alternator - http://the-corrado.net/showthread.php?78654-VR6-90A-7-rib-pulley-alternator-in-the-Glasgow-area

Edited by aclwalker

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Its a pity the alternator is already away from the mk3 I'm breaking, fingers crossed one turns up soon, if you need it collecting and dropped off, let me know

 

---------- Post added at 8:30 PM ---------- Previous post was at 8:29 PM ----------

 

Its a pity the alternator is already away from the mk3 I'm breaking, fingers crossed one turns up soon, if you need it collecting and dropped off, let me know 👍

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