2002 115 hp blowing 20 amp fuse

[npr0520]

I have a 2002 115hp four stroke merc blowing the 20 amp fuse that protects the electric fuel pump, engine control board, ignition coils, injectors and the ISC (not sure what that is). Anyone have an idea on where to start trouble shooting this? I have a volt meter/ohm meter. There is 12.8 volts across the fuse socket - assuming that is not a good thing and there is a dead short some where.

 

[npr0520]

Re: 2002 115 hp blowing 20 amp fuse

I was able to locate the short. It was in one of the wiring harnesses that runs under the plastic air intake manifold. One of the wires in the harness was resting on a bolt head and the insulation had worn through, causing the short circuit. The wire that was cut happened to go to the engine control board - one of the components the fuse was protecting. Saved me an expensive repair.

 

[rvandenheuvel]

Re: 2002 115 hp blowing 20 amp fuse

I am having a similar problem with my 2001 125 Merc and would like to know some of your symptoms, Did your fuse blow right away or did it do it at different times? Mine seems to blow at different times, and I lose every thing. Once I replace the fuse, everything runs ok for a while.