1986 Mercury 115

[Marty Adam]

I have a short that keeps on draining the battery. After three weeks of no use, the new battery is -0- charged.

I disconnected all accessories on the boat and still had a drain on the battery. I think that it is shorting in the motor electrical. What is the best way to isolate the short?

 

[mr 88]

Besides using a DVM and checking for continuity you can disconnect the wiring harness going at the engine and see if you still have a draw.It could be coming from a short in the controls/ign switch/gauges/harness. This way you have eliminated that from being the source, or it is the problem.

 

[Chris1956]

Sometimes rectifiers short to ground. You can check them with an ohmmeter.