Mercruiser alternator question

(imondi) · (imondi) **Join Date: Aug 2010** 10-13-2010, 10:36 AM

My alternator has 2 posts on the back that both look the same. Is there a reason I can't run a cable from each post to each battery? (I have 2 batteries) I think this would help me out since I have it set up now as one battery for starting and one for stereo. The stereo battery does not seem to charge well for some reason, even when nothing is turned on. I think it might have something to do with the isolator.

Thanks guys!

(polarbill) · (polarbill) **Join Date: Jun 2003** 10-13-2010, 10:41 AM

Definately don't do that. I don't know of any of those alternators that have dual output posts. What year is your boat and what engine does it have?

(olmoomba) · (olmoomba) **Join Date: Apr 2010** 10-13-2010, 10:48 AM

agreed - better hook up a voltmeter tester before trying something like that.

(imondi) · (imondi) **Join Date: Aug 2010** 10-13-2010, 10:59 AM

Yeh i was gonna try the voltmeter tonight. It is a 2002 Sanger V210 with a Mercruiser 350 Mag MPI. I will look online and try to find a pic of the back of it!

Thanks alot for the speedy response!

(polarbill) · (polarbill) **Join Date: Jun 2003** 10-13-2010, 11:01 AM

Does it have an alternator that looks like this?

(imondi) · (imondi) **Join Date: Aug 2010** 10-13-2010, 11:05 AM

Yeah, it looks similar to that one only there are 2 posts like the one on the right, one on each side!

(polarbill) · (polarbill) **Join Date: Jun 2003** 10-13-2010, 11:16 AM

Really? The post that comes out of the black plastic cover? That unit looks like it has 2 negative posts but those are the 2 that are down off the actual housing. Get a multimeter and check both posts with the boat running and see if you get 13.8-14.4.