Help with alternator. Where is it?

tbebko

Seaman Apprentice
Joined
Mar 19, 2009
Messages
33
Here is my story. I have a dual purpose battery that I use to start the '89 125 hp Force. When we are moving I might have a simple cd player and a fishfinder on. When i ancor, I will have just the fishfinder on. In 3 - 4 hours I am unable to start the engine. The trolling motor runns on a different battery. How can I test if the alternator is working? Also, the Voltage guage on the dash is not working - I am not sure if its the guage or the alternator.

I am contemplating a dual battery switch but that will not help me if the motor is not charging.

Help. Also, picture of the alternator would be nice.
 

pnwboat

Rear Admiral
Joined
Oct 8, 2007
Messages
4,251
Re: Help with alternator. Where is it?

The "alternator" is underneath the flywheel. It's called the stator. The stator has several windings on it. One set is used to generate voltage for the ignition system. The other coils are used to generate voltage to charge the battery. The battery charging leads from the stator go the the rectifier. The rectifier changes the A.C. voltage produced by the stator into D.C voltage for your battery and accessories. To check it, you need a meter. The rectifier is about 1 1/2 inches square and is usually mounted on the bracket next to the top of the starter. It should have 4 terminals on it. Check battery voltage at the red terminal. Motor should be producing a minimum of 13.5 VDC with the motor turning at a minmum of 2000 RPMs.

Here's a link on how to check/replace one. There are 3 parts to this video.

http://www.youtube.com/watch?v=pAV14aj_DT0

http://www.youtube.com/watch?v=ThX0_E9x1mc

http://www.youtube.com/watch?v=R2ngCNezp8Q
 
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