1986 Thundercraft Legacy

[Johnnyangel16]

Hi all,

Just got an '86 Legacy, and I'm having some starter problems- it supposedly ran fine right before I got it, but once I got it home it would crank like a champ but not spark. I didn't have time to work on it for about a month, but I replaced the battery when i got it and I disconnected it before I walked away for the month. Came back, and all I get is a relay click now- if I ground directly to the back of the starter from the battery, I get a clunk from the solenoid engaging the gear, but it still won't turn. I think I have a bad ground somewhere, but it sounds to me as if I need a starter first- I'm thinking it's possible that the starter was going before, and it wasn't allowing enough current up to spark. Opinions?

 

[Boatin Bob]

Re: 1986 Thundercraft Legacy

What kind of motor is this? I/O or outboard? Does the boat have a safety lanyard/kill switch? If so and it's tripped you can crank all day and not get a spark.

 

[Johnnyangel16]

Re: 1986 Thundercraft Legacy

It's the OMC 3.0L I/O, and I don't see anywhere for a kill switch on the throttle or the dash.

 

[Boatin Bob]

Re: 1986 Thundercraft Legacy

For the NO Spark condition you will need to measure for 12v at the positive post of the coil, for the no cranking condition that sounds like the battery needs to be charged?

Use this link to a wiring diagram for troubleshooting.
You will see the 12v from the battery goes to satrter solenoid and then through a 50 amp fuse and up to the assist solenoid.
From there it goes up to the dash through the purple/red wire to the key and comes back through the yellow/red wire to energize the assist solenoid.
Then the yellow/red wire goes down to energize the starter solenoid which engages the starter and the blue/black wire feeds 12v to the coil.

http://www.selocmarine.com/content/manuals/3404/pdf/340410w150.pdf

 

[Johnnyangel16]

Re: 1986 Thundercraft Legacy

Brand new battery, but also tried a freshly recharged one- still no crank. Removed the starter from the engine, doesn't spin even when grounded directly to the battery... solenoid energizes and the gear comes out to engage, but the motor itself won't turn. I figure it's the starter. I'll start there, then see about the wiring on the no spark condition, if it still exists at that point.

 

[Johnnyangel16]

Re: 1986 Thundercraft Legacy

I know it's been a while, but for closure's sake, it turned out to be a starter and a set of points, and then it fired right up