1986, 70 Johnson not charging

lmuss53

Lieutenant Junior Grade
Joined
Sep 9, 2008
Messages
1,227
The 70 hp Johnson on the Sea Nymph in my sig. is not charging. I have cleaned and checked all connections and have a known good battery. The rectifier has one yellow wire shorted to ground when unhooked the other has resistance. One yellow stator wire has 250 plus DVA volts, the other millivolts, while it was still hooked up. I think the rectifier is shot, but I can't find any diagnosing information to test the stator in a not charging situation. Is there testing that needs to be done to nail down the culprit or is the shorted rectifier enough to point to that as the failed component?
 
Last edited:

jakedaawg

Rear Admiral
Joined
Jun 26, 2012
Messages
4,275
Most likely rectifier, but cdi .com has stator/lighting coil tests.
 

lmuss53

Lieutenant Junior Grade
Joined
Sep 9, 2008
Messages
1,227
Thanks for the reply, I've been all through the CDI stuff. They have tests for overcharging and all sorts of no fire situations, but not for no charge. This motor runs fine, it just isn't charging.
 

jakedaawg

Rear Admiral
Joined
Jun 26, 2012
Messages
4,275
Well, 95/100 its the rectifier. I usually just throw one at it but then again, i allready have them on the shelf and they can go back on the shelf if its not the issue.

Did you do the stator to ground and resistance checks? If so I would throw a rectifier at it.
 

oldboat1

Fleet Admiral
Joined
Apr 3, 2002
Messages
9,612
^^agree, inexpensive fix, at least where cdi replacement parts are concerned.
 

lmuss53

Lieutenant Junior Grade
Joined
Sep 9, 2008
Messages
1,227
Thanks guys, rectifier fixed it.

I also found out someone "might" have turned the Perko switch off while the boat was running a few weeks ago.
 
Top