Ignition fuse problem

[bajaman350]

I just bought a 22' scarab with a 7.4L Mercruiser MPI. The boat had fuel problems before, the electronic fuel pump filter was clogged up. I got that problem fixed, and now I have another problem, so I figured I would try this forum again because it was so helpful the first time. Anyway, the boat gets up on plain and runs for a short time and then all of a sudden, the thing just shuts down and won't restart, I was able to trace out that the ignition fuse was blown, so I changed it, tried it again, same thing. Put it on the trailer, hook some water up to it and it seems to run fine. I have had to be towed in 2 times in a row because of this problem. If anybody has any idea of why the fuse keeps blowing, please help me. It is a 20 amp fuse, and the fuse panel says it is supposed to be a 20 amp fuse for that switch. Any pointers would be appreciated.

 

[tommays]

Re: Ignition fuse problem

I would start buy looking around for any chafed wires that could be shorting out on the motor block<br /><br /><br />After that you would need to start checking the amp draw on the circut to see what it is when its running normaly .<br /><br />I thing you will need a service manual as i have no idea what a normal draw is for you fuel pump and ECM ,ect<br /><br /><br />tommays

 

[bajaman350]

Re: Ignition fuse problem

Thanks for all of the pointers, There is an hour gauge in the engine compartment, and it comes on when you turn the key on. Anyway, the connectors for that had come off and were laying up against the engine, I put new connectors, and away we went... Now boat takes off and hauls, not blows fuse, thanks for all the help!