Voltmeter ?

[Spanish S2]

Hi all, just been out in the S , had done about 10 miles, stopped at some traffic light and looked down at the dash and noticed the needle of the voltmeter fluctuating between 11 & 12 ( not noticed this before ) Back on the revs and stable at just over 13. Any idea's ?

[Smokey Boyer]

I would hazard a guess that the battery is shot, and not holding much charge. Increasing the revs will, I think increase the output from the alternator, and therefore increase the volt meter reading. I assume the needle drops when the revs drop?

Happy to be corrected by an expert on this.

[Maffe]

Have you checked with a multimeter how much it actually have?
Both idle, rev and engine off?

[Oldred_V8S]

Did you have the indicators on?

[dezglidden]

Mine bounces when the indicators are on in time to them! Thought that was something special to my cars tvr electrics!!! Doesn't seem to cause a problem anywhere besides being a bit odd... Part of the tvr charm? Unless others have found it to be an impending sign of doom?!! Figured a something was crossing but haven't ever really investigated...

Dez

[kevroe]

Yes mine bounce up and down in time too. Doesn't seem to cause any problems.

[orange_dodo]

I'm pretty sure that the bouncing is caused by excessive resistance in the wiring. Mine does it too, the voltage does the same thing if I flick the lights on and off. If anyone gets round to rewiring an S then the problem should go away.

[Spanish S2]

Thank's for everybody's input and I may be clutching at straw's here, but I think I may have sorted voltmeter problem. Like Maffe said, tested running speed's with multi-meter O K. Then looking round the engine noticed small coolant hose had come off expansion tank, lost 2 to 3 litres. Witch mean's in this furnace of a country that the fan was running all the time. Anyway, put everything right and been out in S for about an hour and voltmeter has behaved normally. So finger's crossed.