No Power to anything except trim

[Slickboy93]

1989 4.3L Cobra...

Bought it used last week and hasn't been run for 3 years supposedly. Changed oil filters etc and put a new battery in. I checked to see if the trim works and it works great but nothing else works. I got out a tester and started poking around behind the dash. The only hot wire I found was for the radio (which had a direct line to the positive terminal on the battery). I grouned it to the ground on the fuse box and it lit up. I then attached a wire to the positive terminal of the battery and attached it to my tester. I tested the ground on the fuse box and it works. I then tried something else... I touched my tester to the positive terminal on the fuse box, while it was still attached to the positive terminal on the battery,and it lit up???? I figured something is obviously wrong when I touched a wire from the positive terminal to the postive side of the fuse box and got a light.

So where do I go from here? From reading online tonight, it seems that my battery is grounded somewhere between the battery and the instrument panel. So why does my trim work? Is it a whole separate circuit? I have the schematic from my boat, a 1989 four winds, and the electrical schematic for the engine in a selco manual but I can't figure it out for the life of me. I am now wondering if I have a fuse at the starter or somewhere else on the motor? Please help a first time iboater! thanks.

 

[Slickboy93]

Re: No Power to anything except trim

A little more information:

I went ahead and connected a wire from the positive terminal of the battery cable to the postive terminal on the fuse box. Everything came to life EXCEPT the bilge pump and the ignition. This again leads me to believe that there is a fuse(s) somewhere around the engine that I have no diagrams for... anyone?

 

[Boatin Bob]

Re: No Power to anything except trim

The OMC's have 2 50amp fuses right on the engine near the main wiring harness. They are inside black rubber inline fuse holders. There is a separate one just for the power trim and the other one handles everything else engine related. Sounds like that one is probably blown. This link will give you a pretty good wiring diagram to look at. The 2 fuses are up top near the back of the engine and they will each have a heavy gauge red wire feeding them (around 10 ga).

http://www.selocmarine.com/content/manuals/3404/pdf/340410w151.pdf

 

[tysonnathan]

Re: No Power to anything except trim

trace the positive wire from the battery to the fuse box, checking it with the tester all along the way. when you lose current, you found the problem.

 

[Slickboy93]

Re: No Power to anything except trim

Thanks bob, that did it. One of the 50A fuses was blown. Now everything works except the bildge and the engine cranks... but won't start - a question for a different thread.

Thanks again!