2007 Crownline Mercruiser 4.3 Sudden Engine Stop Loss Of Power To Ignition

[Gsex10]

Posted this to Outboards in Error.....Out on the River for an hour and returning home traveling at under 3000 RPM when engine suddenly cuts out. Now no power to Ignition or radio yet Navigation lights, Bilge, and Blower all have power. Alternator was charging and battery remains fully charged. 50 Amp Circuit breaker not tripped. Found a 15 amp mini at top front of engine that was bad but replacement changed nothing. Have watched a few YouTube videos that claim the exact same conditions I am experiencing. The fix in one video being the need to replace the 90amp fuse on Starter cellenoid while the other video claims that replacing the 90 Amp didn't work for him and it ended up being a 15 amp fuse on rear top of motor behind Distributer I have yet to check. Bought this boat new and only issue ever was 2 years ago where key switch wouldn't shut boat off and had to trigger the 50 Amp breaker. Dealer repair said it was a diode that needed replacement and no issues since.....Any Ideas?

 

[alldodge]

Its always good to let us know fully what your working on, and serial numbers are best. Since you said

Dealer repair said it was a diode that needed replacement

This tells me you have a TKS carb, otherwise I would be asking if it was carb or EFI.

Your going to need at least a test light but a voltmeter is better. There is a 20 amp fuse or breaker at the helm which powers the motor, see if it is intact. Then see if you have power on the red/purple wire on the key switch.

 

[QBhoy]

Just on the off chance.....check the lanyard dead man switch isn't moving slightly and also associated wiring.

 

[Gsex10]

Check.......No Issue with Lanyard dead man switch....Carb, not EFI......All Fuses under console (Helm) good

 

[alldodge]

Voltmeter

 

[Bt Doctur]

If you do not have voltage at the output terminal of the alt, the 90A link is bad, and if you find the Red wire there also, remove it and put it directly to the main starter terminal post.. That way you wont be dead in the water. Should the 90A blow again you only lose the alt charge.

 

[achris]

.... Now no power to Ignition or radio yet Navigation lights, Bilge, and Blower all have power...

I assume that includes instruments. I assume your nav light, blige pump and blower are wired seperately to the engine. Good. But it appears the radio feed is from the instrument harness. That's not good (radio dead when engine is dead, as you just found out), you need to move that.

As well as what the others have suggested, also check the engine harness connector, and if the fuse behind the panel is a glass 3AG type, it can look ok, but a bit of corrosion on the ends will stop the pixies flowing. So check the ends of the fuse and the contacts in the fuse holder. I have seen this problem a few times, and if you don't look specifically for it, it's very easy to miss. If you do find corrosion, you can just clean it, but it'll come back. I always change the fuse and holder to a water resistant mini blade fuse holder and fuse (and install them on any new engine I install), that way it's the same as the engine fuses and you only have to carry a single fuse (multiple thereof) to have yourself completely covered. And if you fit a blade fuse, fuse panel, even sweeter.

Chris........

 

[Gsex10]

Thanks to all in the Forum who responded on what to check!. Finally got back up where boat located this past weekend. The 90 amp tested well and the Culprit ended up being a 15 amp mini fuse at top center of engine in the rear behind the distributer. Just happened to find a Youtube video that sent me in that direction. We're all good!

 

[alldodge]

Thanks to all in the Forum who responded on what to check!. Finally got back up where boat located this past weekend. The 90 amp tested well and the Culprit ended up being a 15 amp mini fuse at top center of engine in the rear behind the distributer. Just happened to find a Youtube video that sent me in that direction. We're all good!

Glad your running but would sure like to know what fuse that is. Only motors which have the 15 amp fuse are the EFI ones

 

[Gsex10]

10/2/17 Update......So I was able to get out and run the Boat this weekend prior to winterizing. Boat ran great for all of 10 minutes when this same recently replaced 15 amp fuse located right behind the distributer blew again......Install a new 15 amp fuse and continued to use the boat for almost an hour with no issues and ran it hard before loading out and winterizing...... Maybe the new fuse that only lasted 10 minutes was weak??.......I too wish I knew what that 15 amp fuse was protecting.....Will just keep fuses on board from now on.

 

[alldodge]

Happen to have a serial number?

 

[Gsex10]

I missed that earlier on in the strand when you asked for it. What Serial # would I be looking for to provide?? The engine?

 

[alldodge]

Yes the engine