Battery Not Charging

bwilson2626

Seaman Apprentice
Joined
Aug 12, 2018
Messages
32
My 98 90hp Johnson is only putting out about 0.5volts from the stator. It keeps the motor running, but the battery died on me yesterday after a half day/all night trip. Only ran the Q-Beam for about 5 mins so i dont believe that was the issue.
 
Last edited by a moderator:

F_R

Supreme Mariner
Joined
Jul 7, 2006
Messages
28,195
Well there was your first mistake. Never run the motor with battery disconnected.
 

Vic.S

Rear Admiral
Joined
May 4, 2004
Messages
4,690
My 98 90hp Johnson is only putting out about 0.5volts from the stator. It keeps the motor running, but the battery died on me yesterday after a half day/all night trip. Only ran the Q-Beam for about 5 mins so i dont believe that was the issue.

Suspect the rectifier


Well there was your first mistake. Never run the motor with battery disconnected.

I don't think running the motor with the battery disconnected is a problem

What can blow the rectifier diodes though is disconnecting the battery while the motor is running, This causes a voltage surge which if large enough fries the diodes,

Connecting the battery, even for an instant, with the polarity reversed is another "good" way to kill the rectifier.
 
Last edited:

F_R

Supreme Mariner
Joined
Jul 7, 2006
Messages
28,195
Well ok, so it is possible to rope start it with the battery disconnected. But otherwise, running it with battery disconnected involves disconnecting it while running. In any case, don't do it because it is risky practice.
 

bwilson2626

Seaman Apprentice
Joined
Aug 12, 2018
Messages
32
ok. so i screwed up taking the positive cable off while running. Thats dang handy info, thanks so much. But that doesnt change the fact that it wasnt charging before i did it. Since it wasnt charging even before, what do yall think I should check?
 

bwilson2626

Seaman Apprentice
Joined
Aug 12, 2018
Messages
32
I watched a couple videos on testing the rectifier, but how to tell if the stator is working or not?
 

bwilson2626

Seaman Apprentice
Joined
Aug 12, 2018
Messages
32
Vic.S, Sorry, i missed the top of your post stating suspect the rectifier. The diodes that I probably fried.. they are in the rectifier correct? So replacing the rectifier, if that is in fact my problem, should fix the charging issue?
 

Vic.S

Rear Admiral
Joined
May 4, 2004
Messages
4,690
Vic.S, Sorry, i missed the top of your post stating suspect the rectifier. The diodes that I probably fried.. they are in the rectifier correct? So replacing the rectifier, if that is in fact my problem, should fix the charging issue?

Yes but just replacing bits and pieces without some testing to confirm the diagnosis can become an expensive way of troubleshooting'. (The rectifier/ regulator for your engine is over $200 )
At least check the stator for continuity and AC output

The CDI Electronics Troubleshooting Guide
http://www.cdielectronics.com/wp-content/uploads/2013/02/CDI Troubleshooting Guide - 2012.pdf
should enable you to fully diagnose the problem.
 
Top