Boat won’t start. Trim buttons turn motor over...

[Basshunter05]

I just got a 1994 tournament pro 18 bass tracker with a 75hp mariner. Took it to the lake today and ran great, toward the end of the day I had stopped and been fishing and when get ready to head back to the dock the boat wouldn’t do anything when I turned the key. Finally messed with the Shifter and it started. Got to the dock and turned the boat off to put the trailer in the water and same thing again, no matter what I did I couldn’t get it to turn over. So I got it loaded without starting it and once out of the water I went to trim the motor up and when I hit the trim buttons on the motor the motor turned over and trimmed up at the same time. Now when I hit any of the trim buttons on the boat the motor turns over..... What in the world could be causing this..... I have checked several things. Connections etc. Any ideas would be greatly appreciated. This boat had been sitting for 2-3 years before I got it.

 

[Faztbullet]

Rodent chewed wiring...???

 

[Basshunter05]

I’m sure that’s possible, I haven’t been able to find where any of the wiring looks like it’s been chewed on?

 

[Basshunter05]

Ok so today I traced the wires for the trim pump. I took the green wire off and back on and now everything is fine. Could an electrical component be going bad?

 

[sly_karma]

Ignition key wiring and trim wiring all run in the same harness from the engine cowling forward to the controls. Somewhere in the harness or the control unit, something is/was grounding together. Does your motor has a tilt/trim switch on the cowling? If so, can you replicate the problem there, or is a just happening at the shift control?

 

[Basshunter05]

There are 3 tilt/trim switches on the boat. The problem happened at all 3 switches, And yes one of them was on the cowling.

 

[Basshunter05]

Here is a picture of the wires coming from the trim pump and the wire that I disconnected

 

[sly_karma]

Likely that it's in the controls. Everything bunched in tight in there. No ignition switch or starter solenoid wires at trim pump...

 

[merc850]

You should check out a wiring diagram it looks like there's a wire missing off the small bottom terminal on the lower relay, maybe the starter circuit is finding its power (or ground) thru a different source.

 

[Basshunter05]

Where Can I find a wiring diagram?

 

[sly_karma]

Factory shop manual. It's worth having one for every motor on your boat. You'll use them often.

 

[Dukedog]

where does tha "green" wire coming outta tha plastic sleeve with tha other two (looks like a blue and a white) wires go?
only wires going to solenoids should be same colors as trim motor leads except a common + red on one side and small black grounds..

Blue sky is up and green grass is down thru out all trim buttons and etc.... all switches do have a red 12+......