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View Full Version : New battery - still dead



Pedro
Monday 14th July 2008, 12:14
Well, put new battery in V70 yesterday afternoon and it wouldn't start this morning. Still coming up with - "over voltage, stop safely" and electrical system service warning on dash. Fans still coming on by themselves and rear de-mist led on.

Have checked car as best I can and can't find anything that could be draining the battery that quickly.

Any other ideas or am i going to have to spend a small fortune taking it to a spark?

Cheers


Pedro

cornclose
Monday 14th July 2008, 12:19
Have you measured the battery voltage when the engine is running ? (assuming you could get it to start that is...)

Might be alternator regulator that's playing up, kicking out a higher voltage than it should. I can't see how an 'over voltage' message can be flagged by anything else really, it certainly shouldn't be 'over voltage' when cranking.

Alternatively, I think it might be the ECU which is receiving a higher voltage than it should. Does anyone know what voltage they run at internally ? Can't see it being 12v as they've probably got some kind of regulator which makes them run at a steady 5v or similar. Perhaps it's that which is giving the error and preventing the car from starting.

itguy
Monday 14th July 2008, 12:23
seconded - I have just had a new alternator on my p2 v70 at 72k miles, but this was due to no output rather than over output.

They have a voltage regulator on the back that controls the output.

If I were you I'd whip the alternator out, find your local alternator/starter motor repair shop (the one in leicester is fab) and get them to check it over. If it is the regulator then they are only about a tenner to fix (based on the prices of my chap)

readview
Monday 14th July 2008, 12:56
There was a recall on the fan control unit mounted on the fan housing as they tended to go faulty and set on fire! although whether this is tied in i'm not sure.It may be that if it is not the alternator then a trip to the agents may be required as it would then start to sound like a software problem.