Lost Power And Won't Start

[300sflyer]

I was out in a friends boat last night [1991 5.7 Mercruiser with an Alpha drive] and the engine suddenly quit. We were up on plane at about 3500 RPM, and had been for 10 minutes or so, and it just died suddenly. No prior warning at all. Other items on the boat such as the stereo, bulge pump, horn, VHF radio... ect, are all working fine.

There is no power to the gauges when you turn the ignition on with the key, and the engine will not crank over with the key either. I have checked the 50A breaker, and there is power on both terminals of it, so it seems ok. If I jump the two terminals on the starter slave solenoid, it will crank over, but not keep running. I have checked the main wiring harness, and it seems ok. I'm now stumped...

Thanks in advance for your help!

 

[45Auto]

Re: Lost Power And Won't Start

Is it getting power to the input side of the ignition switch?

Is it getting power to the output side of the ignition switch when it's in the "on" position?

Did someone accidently pull a kill switch lanyard?

 

[300sflyer]

Re: Lost Power And Won't Start

There is no power at the ignition switch on the red wire, [or the other two wires] and the kill switch is fine.

Thanks

 

[300sflyer]

Re: Lost Power And Won't Start

Found the problem... A blown ignition fuse under the dash. There was a 15A one, where it should have been 20A according to the Merc manual.

Thanks