My trim motor will not stop trimming down with the ignition on. With the ignition on it trims up normally. With the ignition off it trims up and down normally no problems forever. With the ignition on and the engine running it will start trimming itself down within 30 seconds or so or it will not stop trimming down once you hit the switch. It doesn'\t matter which switch and it does it with on or the other switch disconnected.
I have a steering wheel trim switch. Disconnected inside the motor and same problem.
Disconnected the trim/tilt switch on the side of the engine cowling and same problem.
I have another relay sitting around here so I hooked that up and same problem.
Backstory: My trim motor burned up last year for an unknown reason. I changed the relay first and then figured out it was the motor that was shot after I hit it with a hammer and it would run enough to trim the motor up. New trim motor and it worked great till now.
It seems that maybe my motor burned up because it was trimming itself down when I was underway and didn't notice.
Question is where does the power/down trim wires cross? Seems I have a short between them maybe. It has to be in the motor past where the plug is where the wires come in from up front *right underneath the relay.
Also if I hit the up trim it will stop trimming down until I release the trim lever. It also stops trimming down once the ignition is turned off. This allowed me to trailer the boat and get home without too much issue.
07-29-2017 07:01 - edited 07-29-2017 07:03
It sounds like a faulty relay assembly but it could be a shorted wire somewhere in the trim switch circuitry.
Because it only happens when the key ON, it may be shorting to a purple wire in either the boat, control, or engine harness.
This may be difficult to find and a factory trained tech could be needed or harnesses temporarily bypassed or substituted to locate the fault.
07-29-2017 12:19 - edited 07-29-2017 12:22
Yeah I agree thanks. I have that other relay here and I bypassed the installed relay and used my spare and it still did it so I know it is not the relay.
I do not have an OMC throttle controller with the built in trim. have a Teleflex Morse control for the throttle and shift and a Pro-Trim switch for the trim on the steering wheel. I traced the wires from the Pro Trim and they come straight back to the engine and to that plug below the relay. Unplugged and same thing happened so I don't think that is it and the only other wiring would be the trim gauge wiring which does seem to be integrated into the trim wiring harness??? Need a V6 Etec wiring scheme.
Purple wire must be ignition. That helps. Somewhere that must be shorting to the trim down wire (green or blue). It is hard to trace the wires once the go into the harness but it looks like they run behind the ECM. I need the actual wiring diagram for this motor.
Blah. Tempted to disconnect the harness and run my own temporary wiring from the pro trim to the trim motor through a relay so I can keep it on the water. I've replaced the ecm and cps on this motor as well. Seems to have some gremlins.
07-29-2017 03:17 - edited 07-29-2017 03:22
Technicians usually have their own "portable keyswich" cables that eliminate the boat wiring from the engine. Something like that would either point to or eliminate the boat wiring harness from being at fault.
Sometimes a weird problem like that is caused by a screw or sharp metal object piercing the wire barness or chafed away wiring insulation or bent pins in a wiring connector