Had a weird electrical situation that left me stranded last fall and want to test the electrical system on my 1980 XS400SG. I got as far as checking the output(?) at the battery while the engine is running at or above 2,000 rpm. The Haynes book says it should be at least 14.5v but mine was only reading about 11.3v. Am I correct to assume that the alternator isn't putting out what it's supposed to? Should I do some further testing on the alternator? Battery was somewhat recently charged. (should I first charge up the battery then do the output test?)

Thoughts?

Had a weird electrical situation that left me stranded last fall and want to test the electrical system on my 1980 XS400SG. I got as far as checking the output(?) at the battery while the engine is running at or above 2,000 rpm. The Haynes book says it should be at least 14.5v but mine was only reading about 11.3v. Am I correct to assume that the alternator isn't putting out what it's supposed to? Should I do some further testing on the alternator? Battery was somewhat recently charged. (should I first charge up the battery then do the output test?)

Thoughts?

the charging system needs a healthy 12v to excite the field coil.

this has been mentioned quite a few times in other threads.

I suggest you use the search facillity top right of the page.

drewps

the charging system needs a healthy 12v to excite the field coil.

this has been mentioned quite a few times in other threads.

I suggest you use the search facillity top right of the page.

drewps

Ok, will do.

Thanks.