Electrical problem after having welding done.

[lukec88]

I took my car for an MOT saturday and it failed on a bit of welding needing doing near the passenger side suspension turret and under the fuse box.
I gave my car to some local guy thismorning that does work on a lot of peoples cars round here at his house. he drove it from my house and was fine. he returned it to my mum whilst i was at work.
my brother went out to it to take it for the retest for me, put the key in and turned it to first click and there was no warning lights, so he put some jump leads on it and started it. he then drove to a petrol station 5 miles away and drove fine until the last mile when it felt underpowered and the lights started lighting up very dim.
he got there and put the fuel in, went back to the car and the battery was flat again. so i got back from work and took the jump leads to him again. started the car and i drove it home from there and it was fine with all the engine power back. then same story when i got within the last mile, lights started coming on but dim. ABS light and oil light came on, was underpowered and spluttering a bit. i got it on to the driveway and as soon as i turned it off i tried to start it up again instantly but the battery was completely flat.

when doing the welding the guy disconnected the battery and had to move the fuse box out of the way to access the area to weld.
im thinking that he has done something when moving the fuse box that is causing this.

does this problem sound familiar to anyone?
any ideas?

[rich318i]

his melted the loom FIRE WILL HAPPEN or fooked the ECU get it checked out

[lukec88]

how would he have melted the loom?? do you think he left the battery connected? he welded my sills a couple of weeks ago and had no problems afterwards.. im not happy because it was running perfect before he did this welding...

[Grrrmachine]

Sounds like the system isn't charging at all. To start with, check all the simple things; that the battery earth cable is firmly connected at both ends, then get it idling and put a multimeter on the battery terminals to confirm it's generating 13.7-14.4V.

If the car runs and drives without the loom going up in a cloud of smoke, the actual wiring is probably alright, and he's forgotten to reconnect something somewhere.

[milescook]

Sounds similar symptoms to my non charging battery.does the battery light come on? Or worse still does it light up at all when you turn the key to the first or second click as it should? If the battery light is blown or won't go on,there's no circuit and the alternator won't charge. Caused me one headache!

[Jos]

how would he have melted the loom?? do you think he left the battery connected? he welded my sills a couple of weeks ago and had no problems afterwards.. im not happy because it was running perfect before he did this welding...

Not much loom in the cills.. fusebox however has lots of wires near it.

What voltage have you got across the battery terminals both engine stop and engine running?

[lukec88]

Charged my battery from 5pm lastnight to 8am this morning. It only got to 50%. I put it on the car and I have a little 12v tester that has lights at 11.5v, 12.0v, 12.6v, 13.2v, 14.5v, 15.5v. I started the car on idle and the lights were all on up to 13.2v. I revved it up to 3k revs and held it there and it didn't once make the 14.5v light even flicker. I then put the headlights on, fans on full and hazard lights on. The 12.0v light was on and the 12.6v one was off. I then turned all the lights off and the fans etc and just let it idle and it went back up so the 13.2v light came back on.. Is that the battery or the alternator??

[Grrrmachine]

That's a very crude test. Alternator normally charges to 14.4, so a healthy alternator won't make a 14.5V light glow, but a sick one may make the 13.2V lamp glow.

I'd bin that tester and get a proper multimeter, seeing as they're only a fiver from B&Q. Without proper numbers, we can't advise further.

If it turns out not to be the alternator, and that you have a massive battery drain somewhere, you'll definitely need a multimeter to find it.

[lukec88]

I have a good mulitmeter somewhere just need to dig it out. Il do some more tests after work..

[Jos]

Borrow a battery from somewhere too, could be either at this stage, battery is easier to check.

[lukec88]

Borrowed a battery it seems fine so no worries now

[milescook]

Ahh, but if your alternator is on it's way out, your borrowed battery will gradually go flat too.

[Grrrmachine]

You've cured the symptom, not the fault. Don't drive it anywhere until you've got a multimeter on it, or you'll kill your borrowed battery and end up owing someone money.

[harry_p]

had similar on my car when the alternator was on it's way out, it needed revving over 4000rpm to kick the charging circuits into action. on cold winters mornings at 5am i had to get it running, de-ice the car and drive onto the mainroad where i could reach 4000rpm without annoying all of the neighbours before the battery ran out.

on the odd occasion i forgot the warning lights and abs light would suddenly appear and i'd lose power. clutch in and a quick blip on the throttle was enough to fire it back to life again.

[lukec88]

You lot were right, I drove it 15 miles for my mot and it passed so that's good, but then went round the corner to get a tyre put on a rim. Put it back in my boot.. Dead battery. Luckily they were a proper garage and did battery checks on both my batteries. My one I took off my car came back as good and so did the other I borrowed. Got it started, put the tester on it and my alternator is only giving 11.47v back to the battery.. So looks like I need an alternator.

[Grrrmachine]

That still doesn't confirm that it's the alternator. If there's a simple issue like a dead battery bulb in the dash cluster (as has been mentioned!) then the alternator won't charge. If there's a loose connection between the alternator and the starter, then the system won't charge. If the accessory belt is slack, the alternator won't charge...

Don't throw parts at it, TEST IT!

[lukec88]

The battery bulb in the cluster works fine. It lights up on first click on ignition then goes out when the car is running. If there was a loose connection between the starter and alternator would it still be giving out 11.47v back to the battery? The aux belt has not long been changed as I had the headgasket done less than 200 miles ago. Maybe I should check that. But then again if the belt was loose would I still be getting 11.47v?

[Grrrmachine]

Where did they test it? At the battery terminals or the starter motor terminals? If it was at the battery terminals, it may be that the alternator is completely disconnected and not giving anything back - the 11.47V is the condition of the battery itself.

The problem may indeed be the alternator, but you need to check all the little things first like earth straps and tightened clamps. If you're lucky, it's a duff diode pack, and these can be replaced without removing the alternator.

[lukec88]

Was tested at the battery.. I'll have to test it at the starter motor terminals tomorrow.. What reading should I get?

[cecotto479]

When welding I always disconnect the battery and the alternate. I've heard of mig damaging the alternator.

[Jim320i]

Luke let me know if you still need the Alternator dropping off, if not, do ring me as its a 30 mile round trip or so for me to drop it off to Matt.

[milescook]

Did they need to refit the alternator for the gasket job? When I replaced my alternator (when all along it was the instrument cluster not being in, and me not realising this was key!), the alternator belt was quite loose.

Turns out I'd got the belt on the outside of the drive wheel, where it looked "right", but wasn't on correctly so not turning properly

Edit: and Jim I still have a spare alternator the one I bought off you is in the car as it's Bosch not re-conditioned so not all lost

[lukec88]

Just done a couple of tests with a proper multimeter. Battery has been on charge for a day. Reading 12.98 when turned off. Alternator connectors get 11.10 with the key at first click. With the car running I got 13.3 from the alternator connectors, starter motor and also at the battery all read the same give or take 0.1

[Grrrmachine]

That's definitely charging too low. First things to check are to rev the engine up to 2-3k and see if you get a higher reading. Secondly, check the alternator belt position and tightness, and then check that all the connections are on firmly. If the welder disconnected the alternator, he might not have tightened everything back up properly.

Unfortunately, if all those check out alright then it may well be the alternator or its regulator pack have gone bad. Only solution is to replace them.

[lukec88]

Changed the alternator today and I'm now getting 13.98 on idle from the battery and 13.82 with headlights and fans on full still on idle.