not charging??

[adgunn]

While out and about this weekend, I noticed my volt gauge only showing 11.5 volts...i checked wirg my multimeter, and got the same at the batteries, running, the voltage was 11.3...I trailered her back to camp, and gave it 6 hrr on the generator at 9 amps...the next day voltag was 12.5, but by the end of the afternoon down to 12.....grr....1979 mercury 900 90 hp 6cyl...any ideas??

 

[BobGinCO]

Re: not charging??

Yup, definitely not charging. Now if only it were as easy to replace the voltage regulator in an outboard as it is in a car. Heck, maybe it is!

 

[Georgesalmon]

Re: not charging??

Easier than a car. No regulator on that engine, just a rectifier. Little black square box about 1.5" X 1.5" near the top on the STBD side just under flywheel. Can disconnect and check with an ohmmeter. Current should go one way but not the other. Check the stator AC voltage on the two yellow wires with engine on muffs if rectifier OK. There are specs on how to do it somewhere in these forums.

Edit: Went and got my manual. Disconnect battery. Disconnect yellow wires on the rectifier. The yellow wires should read .05 to .19 ohms on the R X 1 scale if the stator is good. Disconnect all wires from the rectifier, remember where they were. The rectifier should have continuity from the +, or red, to one of the other terminals one way, reverse leads and not the other. Check the other terminal the same way. If its open both ways its bad, if it has continuity both ways its bad.

 

[MH Hawker]

Re: not charging??

More than liklely the rectifier.