Fuse keeps blowing

[JimMM]

A 1994 Merc 200HP carb outboard with side mount remote single lever control on a 22' deck boat ... the 20A fuse keeps blowing next to the starter solenoid which kills all engine electrical including ignition. The starter solenoid check out o.k., so do the tilt up/down solenoids, temp sensor, lubealert, ignition switch and anything else I can see connected to the fuse line. The motor will crank, start and run for a few seconds, then the fuse blows and everything shuts down.

VOM reading from the red wire that the fuse is on to battery ground is around 3/10ths of an ohm. If I disconnect the plug on the cable from the control box to the instrument panel the reading jumps up to 1.5 megohms. If I read the pins on the connector from the instrument panel I get 14.8 ohms purple (pwr) to ground. There are 7 instruments but they all have a power lead for night lighting from the switch panel. None of the sensor leads (temp, tach, batt voltage, fuel, depth, tilt or depth) are shorted to ground.

Thanks,
Jim

 

[ricksrster]

Re: Fuse keeps blowing

Are your readings from the panel wire plug or the control plug to the panel. You may have a little short in the panel or the control box. The short could also be in the external harness, internal harness, or any of the hot wires on the motor. Unplug your control harness at the motor and start trouble shooting your wiring starting at the instrument panel and working your way back or start at the motor and work your way forward.

 

[JimMM]

Re: Fuse keeps blowing

A spider had worked its way into the tilt/trim gauge and somehow caused an intermittent short when the engine was tilted a certain amount. I pretty much destroyed the gauge trying to get the spider out and detemine the cause of the short. Long story short ... replaced the whole gauge with a new one, and no more spider or blown fuses.