Mercruiser 4.3l All electronics and engine cut out when pushing the Trim button

[Nittany08]

2004 Sea Ray Sport 185 with the carb'd 4.3l Mercruiser. Over the last few months maybe once or twice a month while operating the boat at cruising speed the engine would cut out for a split second and all electronics would also cut out for that same time. The engine would always continue running and the electronics would come back on as well. I checked the battery connections and they were good and even replaced the positive battery cable. However, the issue has persisted.

Last weekend I had the boat out and while getting up on plane and trimming up for cruising everytime I pushed the trim button the engine/electronics cut-out would occur for as long as I held the button. But as soon as I released the button the engine would resume running.

Any ideas on what could be wrong?

Also, not sure if it's related, but starting around the same time this summer that the cut-out problem started occuring, my tach will occasionally swing all the way up to the max reading and then swing back to the current RPM reading. This would happen several times (that I was able to catch) per outing. Note, this is just the tach needle moving, not the engine RPM actually changing.

 

[Rick Stephens]

Start by cleaning all your battery connections at both ends - especially the ground wires. Then work your way to through the rest of the system. Get them shiny clean.

 

[alldodge]

Check the ground cable, remove and clean it from the back of the block

Disconnect the 10 pin motor connector and see what the pins look like and if they need cleaning

 

[Furbird]

Definitely need to check connections first. You have to think about it this way; first it was sporadic, now it's blatant whenever a heavy load (and a trim motor is definitely a heavy load) is active. Eventually anything you turn on will cause it. Gotta start with the easy stuff first.