1990 evinrude 150 (35 amp system ) charging problem

[jwronkow]

I noticed that my system isn't charging the battery. I first noticed it on the GPS system which monitors voltage. I had another rectifier so I just replaced it and was getting 14.5v at the ramp for a quick test. I took the boat out today and noticed everything was fine (30 minutes) then no charging. I just checked the battery with a real volt meter, 12.5 volts, I started it and increased rpm to 2000 and put the voltmeter on it and it read 12.5 volts. I read the A/C voltage at the stator and it was 32V AC. Is that too high? I don't want to replace the rectifier and blow another one. What should I test now? --Thanks

 

[ezeke]

Re: 1990 evinrude 150 (35 amp system ) charging problem

Rectifiers are blown by loose battery cables, switching batteries with the wrong type of switch, disconnecting batteries while the engine is running, bad ignition switches, and just old, bad wiring, especially the battery cables.

The water cooled rectifiers can also be ruined by not having adequate cooling water. I pulled a dead one off a 1990 225 last month that had a solid inch of salt in the cooling fins.