Motor not charging battery

[BOATINGmatt]

I HAVE A 1979 88 HP EVINRUDE. I do not think the motor is charging the battery. my battery is getting much more drained than usual. the volmeter used to rear about a 13 for a freshly charged battery and would read slightly higher while underway..the reading no longer changes and the battery is getting very low after a few uses..Where do I begin..
Thanks

 

[James R]

Re: Motor not charging battery

Disconnect the output wire from the rectifier and measure at the rectifier output with a test meter on DC volts for output of 13volts or better with the motor running. If you get a good output then look to the wiring or your battery. If no output then the chances are that the rectifier is blown.
If your battery is older than 3 yrs try fitting a known young good battery and check the voltage reading. If the battery you are using is an automotive battery not a Marine battery then the battery is probably falling apart inside.

 

[Barnacle_Bill]

Re: Motor not charging battery

Most common problem is the rectifier.