Merc 496 Electrical Issue - Ignition
 

Hey all,

Been racking my head on this one. 2002 Fountain Lightning Classic, Twin 496 HO motors. Couple weeks ago, issue has arose that is causing the Starboard ignition to control both motors. If i turn the Port key to on, it fires the buzzer for Stbd, as well as does the fuel pump prime etc for both motors. It will only start Port but is controlling the "ON" function for both motors. Also once both motors are running, if I turn the Port key off, engine stays running until STBD key is also shut off.

I have so far replaced both ignitions, the 20A push button reset breakers, the engine main 50A breakers and still no dice. Totally baffled by this. Worked fine all season until now. I have the Rinda laptop scan software, didn't find any issues as I was suspecting it wouldn't.

Not even sure how to continue troubleshooting this one.??

Ideas? Suggestions? Thanks in advance!

Did you check all grounds on both engines?

Check the terminals on the backs of the ignigtions/buttons or keys. sounds like you have a ground jumping or touching in a wrong spot, and you are making a loop

Ok I'll double check. I replaced both of them and made sure the wire was good etc

I will have to check for a diagram of the ground locations. I saw the one what I believe is the main ground and it seemed ok but there may be others?