Went for a hand car wash, pressure washers etc. Anyway, as I leave the car wash I notice the battery light and brake light has come on, (I know they are on same circuit) so suspect battery or alternator fault.

I pull in, check under bonnet. There's no sign of water from pressure washers etc, all belts seem fine...

I get home and check with my meter.

All off: 12.74v
Car Running :15.18v
With Load: 14.86

Mmmm... any thoughts guys? Is the running voltage maybe a bit high? Voltage regualtor? Or maybe my battery on the way out? Coincidence with car wash? Groan, could do without this...

 

Did you pressure wash your engine bay?

 

it does seem to be a little high whilst running, try giving the alternator a bit of a spray with some wd40.

 

No, although wondering if the boys doing the car wash got their pressure washers in via intercooler scoop?

 

Tried that, no joy... what I did notice was if I switched my light soff, the battery light went away, then lights back on battery light returned. Now it's there with lights off also. Does this sound liuke a faulty alternator as it's one of these smart charging alternators?

53 plate Blob STi btw...

 

Had the same problem 3 weeks ago, first thought it was the battery, changed that, light still on, ordered a alternator from a breakers only to find the terminal under the red rubber cap had snapped due to heat.

Cut the old terminal off, re-crimped a fresh terminal on and cleaned the point up and its been as good as new ever since.

 

Checked that, all seems fine....

 

Problem found, dampness inside the alternator plug had corroded the pins. Doesn't appear to have been from the pressure wash though. New alternator being fitted...

 

Does it need one? Can't you just clean it up?

 

It seems to have fried the voltage regulator...

 

Is it you that has worked that out or a Garage?

 

My garage sussed it, it was going in today for a new fuel pump anyway. Engine had been out of the car a few months back (not done by me or my garage) and moisture must have got into the connection then...

 

That's bad luck. But hey, a new alternator in the middle of winter is never a bad thing.

 

All sorted now, 2nd hand alternator on and all running fine. Battery seems to be ok, hopefully not damaged any cells....