Re: Battery Charging Question

Posted by Rusty O\'Toole On 2010/2/3 15:38:09

Put the multi meter on the battery and see how many volts you have. Let someone start the engine. When the starter is going it should suck the voltage down. When it starts it should come back up and possibly go over what the unassisted battery had. If you rev the engine to equal a road speed of 30 in high voltage should definitely come up, to 7.2 on a 6 volt car or up to 14.5 volts on a 12 volt car. Then it should level off no matter how fast you rev it.

There are other tests you can do. For example if you put a 12 volt jumper to the field when running the voltage should go higher than 14.5 caution don't do this too long.

This will tell you whether the generator is working well, if it is a question of whether the generator or regulator is at fault.

Your old repair manuals should have a chapter on electrical testing for the more intricate diagnosis.