89' johnson 90 not charging

alumacraft 170

Recruit
Joined
Sep 20, 2024
Messages
4
89' johnson 90hp vro usually doesnt charge. Connections are clean and tight. I tested voltage at idle at the juncton block where the voltage regulator connects to and i get 12.6v. Ive replaced the regulator and today the stator. The flywheel looks fine, no cracks or broken magnets. I used an oem regulator but a cheap caltric stator. The new stator tests .4 ohms and puts out 2v ac. Any ideas? Also do boats normally charge at idle or only higher rpms?
 

Crosbyman

Vice Admiral
Joined
Nov 5, 2006
Messages
5,440
2 vac out the stator is never going to give you 12v+ regulated charge current for the battery.

presumably you measured 2 vac with rect/reg connected

try reading just the yellow AC stator volts ouput without the rect-reg.

charge current goes up with rpms
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
37,818
It should show an increase in voltage at fast idle around 1000 RPM .
 

alumacraft 170

Recruit
Joined
Sep 20, 2024
Messages
4
2 vac out the stator is never going to give you 12v+ regulated charge current for the battery.

presumably you measured 2 vac with rect/reg connected

try reading just the yellow AC stator volts ouput without the rect-reg.

charge current goes up with rpms
I checked voltage with yellow wires disconnected. I put the old stator back on and have 50v ac. I connected the stator and had 14.5v at idle. Took the boat out yesterday, 12.5v at idle and cruising.
 

saltchuckmatt

Commander
Joined
Jul 19, 2019
Messages
2,640
Did you ohm test the rectifier?

You can't run the motor without a battery and other wires not hooked up....it ruins the rectifier.
 

alumacraft 170

Recruit
Joined
Sep 20, 2024
Messages
4
No i didnt test the rectifier. I tested the voltage at the battery and at the terminal block where the rectifier connects to. Same voltage. Yes my meter is good, reads the same as my fish locator. Im gonna run it again this weekend and if its not charging im going to check the output of the staor again.
 

Faztbullet

Supreme Mariner
Joined
Mar 2, 2008
Messages
15,903
If the rect.reg has a purple wire , make sure you have battery voltage on it with key on. as this turns rect/reg on to operate
 
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