Hi guys, hope you can help me on this one.

I had the red battery light on last week, got loads of error messages and the car ended up dying completely on me. The AA chap came out, connected his booster pack and started the car, connected his multimeter to show the voltage at present, which was above 12 volts. He then turned off his booster and the voltage dropped right down to the point the car was starting to idle quite rough. He diagnosed a duff alternator.

So today I have fitted a new alternator, started the car up and the charge light goes off!.

Yippee!. Or so I thought, because when I increased the revs, the sodding light came back on, followed by all the error messages again and trans fail safe. I reduced the revs and the red battery light goes off. I switched off the ignition to clear the trans fail safe message, started the car again and let her idle for a while, then went back to the car to rev it a bit. Same thing happened.

After clearing the errors again, I decided to take the car for a spin but after doing about 2 miles and accelerating a little more to climb a gentle hill, the battery light came on again aswell as HDC inactive, air suspension inactive and trans fail safe.

Anyway, I managed to get the car home and checked the voltage in the hidden menu.

I got:-
Engine off 12 volts
Idle 12.5 volts
When I revved to about 1000 rpm I got 15.5 to 16 volts followed by trans failsafe and other errors!.

What could it be?.

Help me fellow full fatters, your my only hope!. "I got him boxed in like a turtle's pecker!".

Could the alternator have goosed the battery or damaged it badly?

You're battery is u/s.

Sounds like the battery gone fishin'

Thanks guys.

Would a goosed battery cause the alternator to push out a voltage that high, or could I be unlucky with the new alternator being duff?. "I got him boxed in like a turtle's pecker!".

alternater output should be steady at around 14.5 volts, if its pushing out 16 odd volts then thats to much...could be the regulater which is faulty..
sounds like the battery has been overcharged though. ... - .- -.




Y. O. L. O.
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Cheers Stan, I am dubious about now spending money on a new battery if it is in fact the new alternator.

When I first had the problem last week with the old alternator, the battery was severely drained, likely down to about 8volts.

I trickle charged the battery and before changing the alternator today, it started the car with no problems.

It seems to be when the system is under load that it all goes pear shaped. "I got him boxed in like a turtle's pecker!".

What should the idle volts be?.

Mine seems low at 12.5 volts. "I got him boxed in like a turtle's pecker!".

I agree with stan that the regulator is broken

Is the regulator built into the alternator.

If it is that I can't believe my flipping luck putting on a new alternator that is already duff!.  "I got him boxed in like a turtle's pecker!".

idle and revved should hold steady at around 14.5 volts...the regulater is built into your alternater so its faulty i think. ..

sounds lke your batery has gone through the wars with those voltage readings you have given so i would suspect its knackered now.. ... - .- -.




Y. O. L. O.
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Well at 5 am, my alarm was sounding, not that loud, but I had to go down and switch it off.  "I got him boxed in like a turtle's pecker!".

a faulty bonnet switch could cause that.. ... - .- -.




Y. O. L. O.
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Oh boy, she's falling apart I think Stan!. "I got him boxed in like a turtle's pecker!".

at least its all happening before it gets really cold.. ... - .- -.




Y. O. L. O.
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