Johnson wont charge Battery

faubs

Recruit
Joined
May 24, 2005
Messages
4
I have a 1996 Johnson 48 HP that will not charge the battery when running in gear idle etc. The motor will start fine and keep running after the battery leads are disconnected, however when I meter them I only get 0.7 V. The fact that it keeps running leads me to think it’s the voltage regulator. Any thoughts would be appreciated.<br /><br />Faubs
 

wilde1j

Vice Admiral
Joined
Apr 15, 2002
Messages
5,964
Re: Johnson wont charge Battery

If you had a working regulator/rectifier before, you probably don't now. Battery leads should never be disconnected from a running motor. Voltage should be measured only with the cables firmly connected and you should get ~ 13.5 to 14.5 VDC across the battery terminals with the motor idling. If you get 12.5 to 12.7 vdc, you no longer have a working rectifier in all probability, although there are other failure causes, such as wire breaks, stator failure, etc.
 

Basscat 1

Chief Petty Officer
Joined
Feb 11, 2005
Messages
444
Re: Johnson wont charge Battery

Actually, the motor needs to be at a higher rpm than just idle to charge. Rev it up and check it at the battery. Like WildeOne said, never unhook the battery while the engine is running.<br />Its not like a car where you can unhook the battery cables to "field" check the charging system.
 
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