Rectifier Issue? 1992 Johnson 30 HP

[Rocs]

Another issue to resolve?
Water pump, Gear Set, Seals Done.
At the lake this weekend... Looks good.
Went to take the boat back out a couple hours later. Dead battery!
Charged the battery, started right up. couple hours later dead battery!
Installed a Battery Switch, charged battery again... starts right up.
Turn the switch to off, go back and dead battery again.
New battery, again the same thing.
No electronics installed on this project boat yet.
Pulled the rectifier to do a diode test... the red lead is almost triple what the other leads are?
Does that mean it's toast?
J30EEN
rectifier is 511938

 

[Rocs]

Just so you know.
Replaced rectifier
Problem appears to be resolved.
The new rectifier didn't test that much different than the old one, it's just that all were very close to the same reading.

 

[Pappy]

Something with your statement doesn't make sense.
When you installed a battery switch and turn the switch to the off position the engine should have absolutely no connection to the battery to drain it. The battery lead from the engine should terminate at the switch and have an open connection from the switch to the battery yet you stated the battery went dead again in a couple hours. If it was wired correctly there would have been no way for the engine to drain the battery. Again, if wired correctly the engine did not pull the battery down if you did what you said and wired it correctly.
How large (AH) is the battery you are using and how long were you charging it and at what rate? You missed a lot of needed facts in your statement.
The most common reason for a rectifier to fail is reversed polarity when the cables are hooked up. A simple momentary touch will fry it. When failed it will simply not charge the battery.....should not be able to drain one.