Tonight I ran into a very odd boat wiring issue.
I have a 2002 Proline Sport 20CC with a 150hp Mercury outboard. Traveling along in the fog, my motor started to trim itself up and out of the water - all by itself! One thing I noticed is when the motor would trim up the bilge pump came on as well. (No water in the bilge, by the way)
My guess is a common short.
What should I look for in tracing this short?
It could be a ghost. It is that time of year.
BUT, it is probably a short between the trim power wire (red) and trim up wire (blue) and bilge power wire (brow) near the shifting mechanism on your helm.
It is common for wires to be pulled tight to the shift cables. They have some movement when the shifter is actuated and eventually wear through.
Hope this helps,
Haha funny you say that. With the fog rolling in, the lack of visibility, and the boats mind of its own it was like out of a horror movie! I was waiting for a pirate ship to pull up out of the fog! Lol
Anyway I did some troubleshooting this morning and found the trim switch on the motor was passing power through it on the up side even when not depressed. Luckily the problem happened while I was troubleshooting. When I press the trim up on the motor and let go it would continue to trim up for a second before stopping.
When checking with a volt meter. Trim up pressed would pass about 12.6v and when let go would go down to 12.3v and slowly trickle down to about 11.3v. Up side was fine and passed no power if not depressed. So I disconnected that switch and only used the throttle trim switch and it was responsive and stopped without delay when I let go of the button. So it looks like a bad trim switch at the motor.
But it doesn't explain why the bilge came on too, lights and fish finder flickered when that happen also. I left the motor's trim switch disconnected so I guess only time will tell if that was the only problem.
Thanks for your help! I appreciate the quick response and assistance!!