So the 'no charge' warning light came on whilst driving home. This annoyed me, not only because the batter wasn't charging and it was getting dark, but the light is green and it's a light. Surely when your battery isn't charging the last thing you need is an EXTRA light, which ironically went out once the battery died.

Anyway. After an hour on the charger the battery is fully charged, car starts first pull, everything ok, but the battery's not charging.

Alternator brushes are ok and (Burton) VR is earthed ok. My multimeter isn't working so I can't really test anything else, but i'll get a new one in the morning.

However, the theory is that when revved the output at the battery should hit about 14.3 then cut out yes? Is it safe to disconnect the alternator completely and test it's output?

Any other thoughts/test methods?

How do you know the light is green?

I asked my passenger

Sam,
afaik, disconnecting an alternator from the battery whilst the engine is running is asking for big trouble.

Instead, to test its output, run a wire direct from the battery to the exciter terminal on the alternator, bypassing the original wire from the regulator, then keep a close watch on the voltage as the revs are gradually increased.
If it's heading for 15 volts, that should confirm that the problem is most likely not with the alternator.

Next step is to monitor the voltage at the exciter terminal with everything hooked up as normal.
At rest/standstill, there should be 12 volts at that terminal and if everything's working as it should, that voltage should decrease as the engine revs rise.

If there isn't 12 volts at rest, you need to check that the VR is actually receiving 12 volts.

p.s. If your meter is kaput, a 'quick and dirty' test that there's power being delivered to the exciter terminal is to switch the ignition on, then as you pull the exciter lead off its spade, you should see a small spark.

ken

Yes, I had a spark when I unplugged and reconnected the Ex, will get a new multimeter in the morning and see where I'm at.

I thought green light was oil pressure.
Sorry if I've go that wrong.
Don

New multimeter shows steady 12v when I do this.



At rest there's 11.9 at the alternator end of the Ex lead, when revved the Ex terminal on the VR remains steady at 11ish.

Also tried VR direct onto the battery (bypassing ignition switch) and there's no change.

On a car with a later 2cv engine (M28 602 0r 435) you'd be quote right. This is on an old M4 602 so it's charge warning, only fitted to AK350s and early Ami 6s as far as I know.

Never...!!!
Green light is indicator (German and Scandinavian laws)

Oil and Charge is always RED

Edit: Should add, green is also head lights

>>On a car with a later 2cv engine (M28 602 0r 435) you'd be quote right. This is on an old >>M4 602 so it's charge warning, only fitted to AK350s and early Ami 6s as far as I know.

Didn't know what car you had. Hope you get it sorted.
Don