So since I replaced the brushes in the alternator, the voltmeter indicates 0 volts when the ignition is on, whereas it used to indicate 12-ish.

When the engine fires up, this climbs to about 12.5, but it seems to drop when stationary. Is it likely to be the regulator, battery or alternator?

Thanks in advance!

Well presumably there's 12v in the battery or the engine wouldn't start?

Is the battery actually charging, have you tested it with a meter?

I have no reason to believe that the battery isn't charging, because it's not had any trouble in starting the car in the time this has been happening (I've been lazy not bothered to fix this for months).

I don't have a meter to test it, but I can pick one up tomorrow.

The battery will continue to start the car even if its not charging, as you've fitted new brushes I would check the output from the alternator. Should be 12ish at tick over and up to 14 when revved.

Thanks Sam, I'll post some results up tomorrow when i've got a meter.

Re: battery starting car when not charging, i would've thought it would be flat by now? considering how long its been like this.

This is not the fault of the new brushes. You most likely have something funny going on, recheck all your connections especially anything you may have disturbed at around the same time as changing the brushes. When the voltmeter indicates 0 volts it is not connected to a live ignition system. If the voltmeter is giving you a reading that cannot be true, first thing is to fix the voltmeter or it's useless.

that's the thing joolz, the voltmeter gives readings when the engine is running, just not when i turn the ignition on prior to firing it up.

I can't for the life of me think of anywhere in a 2cv wiring loom that should give those results, (apart from inside the alternator). What have you connected the voltmeter to?

Joe,
is this the original voltmeter, referred to as a 'battery meter' in the owners' handbook?

If so, it's a short scale instrument, with the white zone reading between 12.5 and 15.5 volts.
The lower cross-hatched zone is 12.0 to 12.5 volts, the upper zone is 'overcharging', so the needle should sit in the centre of the white part when travelling at normal speeds.

Because it's a 'heated wire' voltmeter, it will tend to give lower readings in cold weather, so does that correspond with when you changed the alternator brushes?

ken

Thanks for the replies guys.

@Ken, yes, original voltmeter/battery meter.

It doesn't read anything until the car starts. So does this mean that the battery isn't developing enough volts to register on the meter, but turn the engine over? in which case surely this wouldn't have lasted months, as I would have expected the battery to be charged back up by then?

Brushes were changed ages ago, it did this in the summer before it was off the road.