12.6v at idle???????

[davetherave1970]

Can anyone be bothered to test this in this heat?
Had a flat batt twice in two weeks now. Had a new alternator and big fuse but on idle the voltage at the batt is 12.6v
Have to get the revs up above 1,500 before it reads 13.5v
Anyone know if this is normal? I would have thought it would charge a little bit at idle!
Oh BTW 98 4.5 :)

[Apache]

Strange one that, I'd have said your regulator appears to be shagged but that is part of the deal these days when you replace an alternator.
Take it to an auto electrician and do a proper check of the battery with a big choke and ammeter, if he wanders off for a multimeter forget it. If the battery checks out you're looking at a bad earth or wiring

[Julian64]

If any help, My Cerb is raising the battery to 13.6 Volts at tickover approx 900rpm.

[davetherave1970]

Yep, that's a help.

Thanks guys.