Mariner Alternator

[tcavanau]

I have a 1984 Mariner 90 hp that is not charging the battery. I took the cover off to look at the alternator and can't find it. Is this the type that has the windings in the flywheel and sort of works like a magneto? How do I find and check it and has there been a common problem with them? Thanks

 

[WillyBWright]

Re: Mariner Alternator

Welcome to iboats.<br /><br />They're pretty dependable. There's a set of windings under the flywheel. Find the little square black rectifier and remove the two yellow wires. Check the resistance between the wires. I don't have the spec, but if you have continuity it's probably good. Next, check one lead for a short to ground. If there is, it's bad.<br /><br />It's probably the rectifier. Loose or backward battery connections take them out. That's the most common cause for a charging system failure on those (by a bunch).

 

[tcavanau]

Re: Mariner Alternator

I checked the two yellow wires with my Simpson voltmeter and there was continuity and a small amount of resistance. I also did a front to back on the rectifier posts and to me it seems ok. I don't exactly know what kind of a rectifier it is ie: half wave, full wave, or bridge. Is there a voltage regulator somewhere also?