Here's a wierd one

[sgarre13]

Guys, new to the forum, basically we've had a T22 2002my 1.8 auto avensis for a couple of years and it's been so reliable. But today it starts with the problems. So the symptoms are, when you press on the gas, the abs light comes on, as does the brake light, the temp needle drops to cold and the heater fan goes crazy, all simultaneously. Haven't had chance to fault code or anything, but my thought is are all these on the same grounding point? Anyone seen anything like this before?

[Mooly]

All those unrelated issues would point to some common cause such as poor grounding somewhere. I guess the first check has to be Battery terminal security and then look for any obvious corrosion points in the under bonnet area.

All of that reminds me of a similar problem I had with a new Audi A4. The wipers would come on on their own, the fuel gauge read incorrectly, turning the air con on caused the cassette player to eject the tape...

The problem was an earth point bolt that was hanging off inside the passenger footwell. Yours wont be anything so obscure I'm sure, mine was just typical (terrible) Audi quality and was just one fault out of dozens in the time I had the car.

Check your Battery terminals first. 

   

 

  

[sgarre13]

Thanks Mooly, my thoughts as well.

Anyway Battery was flat when we got back to the car and we had to be rescued back home. Before being rescued the Battery was tested by the rescue guy and it showed 9.5volts, and when we jumped it and started the engine, we had 14volts at the Battery and across the engine earth, so charging seems to be happening. Just fitted a new battery but still this wierd connection of symptoms between temperature gauge and ABS light when you press the throttle, also battery light doesn't always go out, and now I suppose the possibility that the battery will go flat again.

Trouble is electrics are not my forte and studying the diagrams I have found on the net, I'm really struggling to get to a common link between them. I can't really see anything obvious in the engine bay which could suggest a fault. The only thing that looks like a possible is the blue wire from the battery positive which looks like it goes to the fuse box alongside, that wire seems like it could be frayed on the inside, but there's no obvious sign on the outside, i.e. it seems a bit soft when you wiggle it (ooh err missus).

Due to pressing time I'm gonna have to chuck this one into the garage we have next door.

[sgarre13]

An extra thought, could this be the alternator? I've heard stories of wierd stuff happening when the regulator fails on other cars.

I'll check what the voltage does with a throttle blip later as our rescue guy only tested when it was idling.

[furtula]

Yes, could very well be the alternator, there was a topic 2 weeks ago where a faulty alternator caused the break and abs lights to come on if the rpms go over 1k, that is, anything over idle more or less.

I think you might have the same issue, as the faulty alternator will actually empty the Battery very fast.

If you have a multi meter, it would be best to do a parasitic drain test, it's pretty easy and you can see if on youtube.

Even if the alternator is charging, it can still be faulty, so do not take it as being in fully working order.

[sgarre13]

Excellent hoping I've got the same issue. As it did have the abs and brake lamp on just with a gentle press of the throttle, so lifting the revs easily over 1000rpm I guess. Anyway just bought the same part number alternator from a local breaker (off a 1.4 vvti corolla in Peterlee) so I'll pick that up tomorrow evening and try to fit.

[furtula]

Would have been better to check it with multi meter first which costs like 1/5th of the used alternator , to make sure that is the actual issue.

It's a handy tool to have anyway, a must if you plan on doing anything electrical related on your car.

Good luck, hope the hunch was correct.

[Mooly]

The heavy Battery drain does point to a possible alternator issue and yes, it would be interesting to know what the voltage does as the revs increase. I wonder if there is an over volts situation when running rather than the more usual under voltage. You have so many unrelated areas affected, fan, temperature gauge and so on that its impossible to call on this one without further tests. 

If you have a new Battery fitted then it might be wise to disconnect that now and so stop any deep discharge if the alternator is in fact faulty. Deep discharge and significant over volts are both Battery killers. 

[sgarre13]

New alternator fitted last night (and of course new battery), all working fine now, no warning lights or bouncing temperature gauges!!

[sgarre13]

Mooly and furtula, Many thanks for your help.

[Mooly]

That's great news. Excellent.