Originally Posted by jezza2011
also put the meter on to the AC setting and see if there is any AC voltage there.
if there is then the regulator is not working. ( rectifer breaking down)
Start at the alternator itself before the rectifier and voltage regulator (which are often one epoxy potted unit anyway). I don't think this is a cabling issue. But basically I would start:
1) AC voltage across alternator output
2) AC amps at regulator output
3) DC voltage across rectifier-regulator output
4) DC amps at regulator output
5) DC voltage at battery posts
6) DC amps at positive battery terminal
7) Then DC amps at return points to alternator again.
The amps are small enough you should be able to check both the voltage and then disconnect the positive cable and check the amps at each point. But check that your meter can handle the load. Clamp the meter leads to the disconnect lead with pliers. If your meter can't handle the amps you can get one of the wrap around types to check amperage.
I would have all the other loads turned off for this demo.