Wiring woes solved

[Grumpyrockfarmer]

1969 Mercury 650 Wouldn't shut off with key, opened Mercontrol and was greeted with bared wires arcing. Now no spark in engine. Seloc says type III ignition. Fixed the harness.<br />Anyone got a more step by step troubleshooting process for this engine? Serial# 2507245<br />Would appreciate any help!<br />Thanks

 

[ronmold]

Re: Wiring woes solved

Older non-EFI motors had a magneto-style ignition that runs when the black/yel lead in the harness is REMOVED from ground. This lead grounds when you turn off the key thus killing the motor. The ignition has nothing to do with the battery or 12V+ leads. Check w/ ohmmeter or 12v test light to make sure the black/yel lead on the switchbox is not grounded.

 

[bucksaw]

Re: Wiring woes solved

I have the same motor, mine wouldn't shut off. Took control all apart, put all new wires on. I used smaller wire, so it was easy to close and not bunched up. It has worked great all summer, now hears the best part. All it really was in the first place, was a loose harness plug on the motor. Found every thing in the seloc book.

 

[Grumpyrockfarmer]

Re: Wiring woes solved

Thanks guys-<br />Fixing harness today and will try on motor this weekend. The concern was that I blew the coil or switchbox - I guess I'll see.

 

[Grumpyrockfarmer]

Re: Wiring woes solved

Thanks very much for the advice!!! It was the switchbox. Also found a few other loose wires.<br />Running great, now i just have to stiffen my transom!