Poss. electrical fault with M Reg Astra - holly1
Oh this car is really starting to get to me - its now developed another fault, possibly electrical. Basically, it ran fine for a few weeks then the airbag warning light lit, petrol & temp gauges re-set themselves to zero, CD player stopped working but as soon as they all went wrong it all started working again.

Month or so has now passed with no problems, until today.

First thing I noticed was the clock on the CD player was blank - its usually lit with the time. Got to our destination and halfway back when the airbag light came on as before, temp & fuel gauges re-set.

Bit further down the road the engine warning light flickered on and off and the engine started to run a bit roughly - however this was all for only a few seconds and car started running perfectly normally again, but the airbag light stayed on and fuel & temp gauges were still on zero.

Any suggestions before I pop to the garage for another huge bill.

Poss. electrical fault with M Reg Astra - Number_Cruncher

I would probably begin by checking the connections to the relevant fuses. Sometimes the connections to the fuse become damaged.

If you find this is the problem, I would suggest that the affected fuses are by-passed using an inline fuse. Obviously, don't by-pass the fuse with anything other than a fuse of the correct rating.

I hope that helps...

Poss. electrical fault with M Reg Astra - holly1
Thanks number_cruncher. One thing you with gather from my previous posts is that I just hate anything electrical, its one area I just cannot get my head around.

At least I now have some idea of where to start!
Faulty Battery/Alternator M Reg Astra - holly1
Im getting a bit confused now with regards to whether the battery or alternator at fault - bit of history... Both replaced, worked fine for 5 - 6 weeks, then airbag warning light came on & stayed on. Fuel & temp gauges died, but all fuses appeared OK.

Booked into garage to see if their computer can trace where fault lies. Car not used for approx. 5 days & battery was completely flat. To begin with it would not charge - tester read faulty - but then started charging but took ages.

Connected it back up and drove less than half a mile and car died. RAC called, said battery was at faulty because its terminals are loose - you can actually move them. He put his battery in the car and connected his multimeter to it and car started first time. The reading he achieved was 12.9 and rising & all previously lit warning lights were now out and gauges working correctly.

Car dove to garage OK, they hooked it up to their computer, agreed battery is faulty but now say alternator is faulty too.

Correct me if I am wrong, but if the reading the RAC man got was 12.9 and rising whilst his battery was connected then doesnt that mean the alternator is working and charging the battery?

Plan to get rid of the car now but need to get it working first.

Faulty Battery/Alternator M Reg Astra - Number_Cruncher
Hi Daisy1,

I don't know what diagnosis techniques your garage used. It is possible to have an alternator which charges the battery, but is still faulty. For example, if a diode fails, you get a very "noisy" battery voltage when looked at with an oscilloscope - you should get a relatively smooth full wave rectification ripple.

Also, 12.9 volts is a bit weedy - I'd expect about 14 volts with the engine running at 2000 - 3000 rpm.

Loose terminals are never good!

I'm pretty sure there are other faults lurking here. One thing to check on Vauxhalls is the earth lead between the alternator and the engine block if your car has one - these have caused all manner of trouble.

Faulty Battery/Alternator M Reg Astra - holly1
Thanks number_cruncher, since my last post I have spoken with the garage. Yes the main problem is the battery so its now been replaced. The 12.9 reading did actually increase to 13.5 within seconds of the engine running.

As for the alternator, it appears that it does work properly. The problem was that Garage A (who fitted the replacement one) didnt return the car to Garage B (who are the only local place with the correct kit) to have the fault code cancelled out of the ECU.

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