50 ELP loss of gauges, trim, and no start

G

Guest

Guest
A few weeks ago I noticed that when driving the boat all the gauges would drop to zero and the trim on the throttle didn't work (engine would stay running). If the engine is shut off it won't start again. However, if you go back to the motor trim switch and play with the up and down mode the gauges eventually go back up and the engine can start again.

At first I thought is was feedback or grounding issue. After not being able to isolate the problem convinced I had a bad key switch it was replaced, then a new starter solenoid, and then a voltage regulator. None of these were my problem. If I go to the motor and start disconnecting connections one at a time I cannot reproduce the problem. I can reproduce the problem if I pull the 20-amp fuse that is located up by the cowl or disconnect wires from the solenoid.

Once the gauges are up turning the key from on to off several times will create the same problem. Then back to the motor trim again?

The problem gets worse with every use of the engine.

Thoughts? Loose wire? If so, I cannot find it. Bad wiring harness? I think everything has been jiggled and nothing. It's not a battery connection issue. That was the first thing I checked. Again the feedback from using the motor trim switch is temporarily fixing the problem.

My Merc service manual said when in doubt it?s a grounding issue. Not sure it is. After reading this if know the answer I'd gladly pay you for your time. Since I live in rural MN most dealers have a 3-4 week waiting period to have a motor looked at.
 
G

Guest

Guest
Re: 50 ELP loss of gauges, trim, and no start

Also disconnecting the main harness will reproduce the same problem.
 
G

Guest

Guest
Re: 50 ELP loss of gauges, trim, and no start

I think the problem is solved. It was the main harness. However after installing the new harness my solenoid just buzzes. The color coded wires would be hard to screw up and the only wires not color coded are the oil sensor.

The solenoid is only two weeks old. Do I have a power problem or a solenoid problem?
 
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