Strange voltage reading in Nova

[pierskittel]

Hi all

Due to the digital voltmeter, I can only know the voltage level (above 12v) to be the following:

between 12v and 13v
between 13v and 14.5v
between 14.5v and 15.5v.

Anyway, since getting the voltmeter 3 years ago, when the engine is running, 99.9% of the time it always read 13v-14.5v. Rarely shows 12-13v apart from really cold winter days where the wipers, lights, rear windscreen demister, blower, everything is on. Car went for a half service, MoT, and cambelt change on Saturday, and ever since, the voltmeter fluctuates between 12-13v and 13-14.5v, preferring to stay in the 12-13v zone most of the time. On the way back from work today, the voltmeter never crept over 13v. The voltage warning light never comes on.

I've checked the drive belt and the battery terminals and they both seem okay.

Any ideas why this happens? Is it possible that the battery is knackered? Or have the garage done summat?

Thanks very much for your help in advance

Cheers - Piers

[ade]

you got a decent stereo system?

Not saying it happened but possible the garage were listening to the radio or cd's with car turned off.

This may have dropped voltage a bit?

Dunno though.

Check alternator - just incase then changingf belts its been knocked or damaged. If the belts wrong tension it'll squeel like a pig

Ade

[pierskittel]

Yeah I do - but I didn't bring the face off, so they couldn't have turned on the head unit anyway. Have driven the car for 150 miles since, should have charged up the battery. I'm starting to suspect that the battery's knackered, but I'm loath to pay ?50 or so for a good battery to find it hasn't solved the problem. Checked the drive belt (as best as I could) it seemed ok to me, tight and stuff. Can't hear it though...

Cheers for your help tho :)

Piers

[Dicko]

batery fully charged shud be around 12.7, half charge = 12v, going flat = below 11v, when on charge shud read around 13.7 as thats what the alt shud output.
however if the regulator is screwed on your alt it can overcharge, usualy would read over 14v if this happens. is the volt meter conected inside car, or u mean like a multimeter you keep conecting?

maybe they replaced the regulator on the alternator?

i doubt its the batery as even when there pretty dead the alternator would make it still read 13.7v.

but just take the bat out and make sure the de-ironised water leves in it are ok :)

[rhumphris]

If u have a Halfords near you, they check your batt for free

[Cooch]

when running battery should charge between 13-14.5 volts when not on should be between 12-12.5 volts. Take the battery off charge it and see if it holds the charge or charges in the high 13's if so its ok.