Electrics: 850 all dash warning lights on/off when running

[mugball]

I have a 94 850 GLT 2.0 which threw up some gremlins this morning!

Early morning, start no problem, demister on full blast, wipers going, full headlights, all normal, but then after about 2 minutes all warning lights on dash came on.

Knocked off engine, restarted, lights did not go out after engine on.

Drove a little, upped the revs, lights out, driving along happily no problem, but if you touch anything electrical - eg indicators, lights on again. They even come on if you touch the brakes.

They turn off again almost as soon as they come on, eg as soon as you knock indicator off, warning lights off too.

Slowing to a stop, lights on at idle, take up the revs and they go out.

Abandoned journey, detour to mechanic, surprised to see me again so soon as he just replaced balljoint two days ago. I asked him if he could have knocked anything out of place, but he was certain that was not the problem/

He took a quick look with car running and stationary, tested battery, showing healthy voltage, and was happy that alternator was charging OK. After that there was not much more he could do, as he was too busy to look at it any further this morning.

Have cleaned battery terminals, checked earths and all looks good, swapped out a for a new fully charged battery but still same result.

At the moment I am thinking my next best step is a new alternator, but thought I'd ask here in case anybody has any better ideas?!

[VerdeV70]

Check the fuse box? It might sound daft, but if it has been opened and not closed properly, and you have had rain etc, you can have some ingress and that causes all kinds of problems.

Had a Skoda Octavia a few years back, for no explanation it had all kinds of strange electrical gremlins, and then would be fine. Took it through a car wash, and it then refused to turn off once I had been through. Key was out of the ignition and the car was trying to maintain spark. Anyway, took it in, had it with an auto electrician in and out for weeks, and the issue, water ingress in the fuse box as the lid hadn't shut properly.

[mugball]

Originally Posted by VerdeV70

Check the fuse box? It might sound daft, but if it has been opened and not closed properly, and you have had rain etc, you can have some ingress and that causes all kinds of problems.

Had a Skoda Octavia a few years back, for no explanation it had all kinds of strange electrical gremlins, and then would be fine. Took it through a car wash, and it then refused to turn off once I had been through. Key was out of the ignition and the car was trying to maintain spark. Anyway, took it in, had it with an auto electrician in and out for weeks, and the issue, water ingress in the fuse box as the lid hadn't shut properly.

Thanks, not a bad idea, but no joy. Just took a look at the fuse box, bone dry and shut tight. All looks well in there.

[VerdeV70]

Originally Posted by mugball

Thanks, not a bad idea, but no joy. Just took a look at the fuse box, bone dry and shut tight. All looks well in there.

Your more than welcome. The other suggestion I could offer is checking the connection behind the speedo/light cluster. It may be that you just have some dodgy wiring somewhere.

If the battery is showing good V and the alternator appears to be working, my guess is you have a wiring fault somewhere, especially if the fuse box is bone dry

[4x4]

Sounds like a voltage problem, get the alternator checked by someone with the correct test equipment

[mugball]

Originally Posted by VerdeV70

Your more than welcome. The other suggestion I could offer is checking the connection behind the speedo/light cluster. It may be that you just have some dodgy wiring somewhere.

If the battery is showing good V and the alternator appears to be working, my guess is you have a wiring fault somewhere, especially if the fuse box is bone dry

This concurs with the vague impression I got from mechanic.

I am just very aware that it is only happening at low revs, quick squirt of the throttle and all lights go out. Surely increased revs would make no difference to loose wiring in cluster?

Car have car sitting idling with headlights and heater on full, will see if it is draining battery. Unfortunately my multimeter toast so will have to try and run it down!

I'm kind of in a pickle, as have to take it on a 700+ mile round trip imminently. If it is just dodgy wiring, happy to run that gauntlet. Less so if it is dodgy alternator!

[mugball]

So, as it's idling, have just been sticking my ears around the engine bay to no avail, but my nose picked up a slight burning smell coming from alternator. Not strong, get the fire extinguisher out, but definitely kind of off.

Would that make any sense?

[mugball]

Left it ticking over for a while with electrics blaring, turned it off, then tried to restart, battery dead as dodo.

I am now looking for a new alternator.

[VerdeV70]

Originally Posted by mugball

Left it ticking over for a while with electrics blaring, turned it off, then tried to restart, battery dead as dodo.

I am now looking for a new alternator.

Well, at least we know what it was

[Luxobarge]

Are you sure it's the alternator, not the battery itself?