Question Chevy 350 in a boat, no spark until someone jumped a wire from battery + - Page 2

96ws6t/a · 02-03-2010, 04:51 PM

it may not be the coil it could just be a bad wire to the coil

Dj Brady · 02-03-2010, 05:05 PM

Cool, thanks for the heads up.
I don't have any schematics for an old ignition system and I'm not really familiar with it. Does that lead come from the key or is it from a relay?

1963SS · 02-03-2010, 06:26 PM

Is it a Mercruiser, about what year? There's a plug that connects all the engine wiring to the boat wiring. These plugs are notorious for getting corroded. That could be part of it. There is also an interrupter switch beside the carb on the intake. If it is not in the correct position or is out of alignment, the boat won't start. There's a lot of things it could be but without more info it's difficult to diagnose a problem.

I know about boats only because I've owned one for 30 years, of course that makes me a boat mechanic.

Either work on a boat or sit at the dock and drink beer. Both work for me.

ShowNoMercy · 02-03-2010, 06:33 PM

Quote:

Originally Posted by 1963SS

Is it a Mercruiser, about what year? There's a plug that connects all the engine wiring to the boat wiring. These plugs are notorious for getting corroded. That could be part of it. There is also an interrupter switch beside the carb on the intake. If it is not in the correct position or is out of alignment, the boat won't start. There's a lot of things it could be but without more info it's difficult to diagnose a problem.

I know about boats only because I've owned one for 30 years, of course that makes me a boat mechanic.

Either work on a boat or sit at the dock and drink beer. Both work for me.

Its way before Brunswick... OMC.

96ws6t/a · 02-03-2010, 07:40 PM

i dont think there is any relays for the 12v to the coil. the wire is going to come out of the main harness for the engine it is going to be a big plug with a bunch of wires going to it and out of it. i think its the purple wire but i could be wrong i cant quite remember off hand.

Dj Brady · 02-03-2010, 09:52 PM

awesome. I'll try to go down this weekend and tinker.... I just hate effing around in the cold... bleh

thanks again guys for all the info!

Dj Brady · 03-06-2010, 02:56 PM

I got some pics... sorry it's so dark.. not a lot of light in the engine bay.

maybe this will help though?

Dj Brady · 03-08-2010, 09:13 AM

*tap tap* is this thing on?

Dj Brady · 03-09-2010, 06:49 PM

:lookleave

five7kid · 03-11-2010, 11:08 AM

I see it has an oil pressure ignition cut-off switch. With corroded terminals.

What is that yellow wire that is pulled out of the crimp splice? That blue crimp splice looks horrible, too.

Chase that stuff down. Fix what isn't working.

Dj Brady · 03-11-2010, 11:28 AM

Interesting. What unit is the oil pressure cutoff?

Tested the coil last night. 12v to +, nothing coming out of - Pulled coil, it sloshed. Putting new coil on tonight.
Agreed, wiring is nightmare but selling the boat. Potential new owner is well aware of those issues. I just need it to run for him.

Dj Brady · 03-11-2010, 07:42 PM

Fired it right up today.. Bad coil.

Thanks for all the help, suggestions and advice y'all!

five7kid · 03-12-2010, 10:45 AM

If jumping a hot wire to "something" on the ignition got it to start, it wasn't a bad coil.

More likely replacing the coil cleaned up whatever poor connection was keeping it from starting.

Dj Brady · 03-17-2010, 12:00 PM

tested the coil. Bad coil.
He was jumping to the secondary.