OMC Cobra trim problem

[LR28]

1991 Four Winns 170 with 3.0 OMC Cobra. Down trim works fine but whenever I try to trim up it pops the circuit breaker on the CB/relay assy. It will even do this when the trim motor is disconnected. I have taken electrical resistance readings on the harness from the switch to the connector as well as the harness from the 3 prong connector to the motor with nothing jumping out at me. Thought it was a faulty CB/relay so I replaced it, still the same problem. Any ideas?

 

[LR28]

Re: OMC Cobra trim problem

Now that I've taken a break and had time to think about this problem.........I have verified that the switch harness is working correctly and have narrowed my problem down to the harness that connects to the cb/relay or the relay itself. I sketched out a quick wiring diagram using two automotive style relays which can be mounted outside of the engine compartment or enclosed in a J-box style apparatus. One would be for the up circuit and the other for the down circuit. Cost would be about $20 versus $100+ for the original OMC part. I'm all for maintaining originality however this slight modification makes more sense given my current situation. Any thoughts?

 

[LR28]

Re: OMC Cobra trim problem

Quick update, I decided to go ahead as planned and for any others tired of looking around for Cobra trim relays this might be a good plan for you. I bought two insulated marine starter solenoids (ST80) at Napa and just wired those up instead of using the original cb/relay. Obviously you need to protect this circuit so whatever you decide on using will work for you. All said and done this was so much easier and cheaper than searching around for used crap that doesn't work.

 

[RRitt]

Re: OMC Cobra trim problem

Now that I've taken a break and had time to think about this problem.........I have verified that the switch harness is working correctly and have narrowed my problem down to the harness that connects to the cb/relay or the relay itself. I sketched out a quick wiring diagram using two automotive style relays which can be mounted outside of the engine compartment or enclosed in a J-box style apparatus. One would be for the up circuit and the other for the down circuit. Cost would be about $20 versus $100+ for the original OMC part. I'm all for maintaining originality however this slight modification makes more sense given my current situation. Any thoughts?

before you re-invent the wheel it might make sense to make sure that the old one is broken. Your most likely suspect in this scenario is a short inside your trim motor. disconnect motor and see if relays still trip breakers.

 

[LR28]

Re: OMC Cobra trim problem

It will even do this when the trim motor is disconnected.

 

[bruceb58]

Re: OMC Cobra trim problem

Sounds like a faulty relay. Swap relays and see if the problems moves to popping when you select down.