1990 40hp Johnson Charging Problem...s

[Ovrkil]

I have been working on a Johnson 40 and the battery goes dead after a day or so. So here are my findings,
the voltage at the battery is around 12.7v at 4000ish rpm it is at 12.9-13v at best, I changed the rectifier and I have 18v out of the stator at high rpm, checking between the yellows on the rectifier I have 12.5ish volts is that normal? I think it is supposed to be 13-14 v right? How else can I test to see if the stator and rectifier are working properly?

 

[samo_ott]

Re: 1990 40hp Johnson Charging Problem...s

A fully charged battery should never die in a day. Have you load tested the battery? Is it old?

 

[tashasdaddy]

Re: 1990 40hp Johnson Charging Problem...s

sounds like you have a dead cell in battery.. have it load tested at auto parts store, usually free.

 

[Ovrkil]

Re: 1990 40hp Johnson Charging Problem...s

The battery is only about a month or so old. No I have not load tested it yet. Will do.

 

[samo_ott]

Re: 1990 40hp Johnson Charging Problem...s

Is something left on and draining it? Check the current flow when all is off to see if there is a hidden drain on it.