Mercruiser 225 breaker trips when key is turned to start

[rebars1]

The drought is finally partially over and my local lake is allowing boat launching again. My boat has been in dry storage there and has not been run for about three years. When I went to clean and prep it this weekend, the circuit breaker would immediately trip when I turned the key from "on" to "start" (no solenoid click or engine cranking). After a short time the breaker would re-set, but would trip again when I would try to crank the engine. Could this be caused from bad battery cables? With key in the "on" position the gauges and electronics work fine.

 

[Bt Doctur]

? the breaker is a 50 amp is must be reset manually

 

[Scotvl]

Are you talking about a breaker near the ignition at the helm or the 50 amp red breaker on the motor? If it's the round breaker next to the ignition that you have to keep pushing in until it's cool enough to reset it could be one of the many accessories instrumentation or sensors connected to helm power that is tripping it. Does it trip when you first power the key on or when you turn it all the way to start the engine?

 

[rebars1]

There are some fuses at the helm, but no breakers. Everything works with the key in the "on" position (gauges, bilge pump, etc.) but when the key is turned to "start", I hear a click at the engine and everything cuts out and there is no cranking of the engine. After a short time, the gauges come back on. I will check the cables to make sure that the squirrels did not chew through the insulation.

 

[AlRichmond]

There are some fuses at the helm, but no breakers. Everything works with the key in the "on" position (gauges, bilge pump, etc.) but when the key is turned to "start", I hear a click at the engine and everything cuts out and there is no cranking of the engine. After a short time, the gauges come back on. I will check the cables to make sure that the squirrels did not chew through the insulation.

Hi rebars1, I have exactly the same problem with my 2004 Mercruiser 3.0. Just wondering what you eventually identified as the problem?