Jumpering Trim Pump

[haulnazz15]

The issue is after a complete transom rebuild, this is the last piece of the puzzle, and I likely have one wire in the wrong place. The trim pump clicks when pressing the up/up-out (trailer) buttons, but makes no sound when pressing the down button or up button by themselves (thus no movement). The system was pretty much drained of all oil, so the system needs to be bled, but I have filled the resevior and have bleeding procedures once I can get the pump to operate.

Alright, not many people seem to know much about diagnosing the wiring on a single-solenoid trim pump from the 1970's, so I'm going to try this:

1) I will try and reverse the two connections that go to the trim limit switch in the gimbal housing to see if that fixed my problem.

2)If that doesn't work, I will buy a piece of wire and simply bypass the solenoid/trim limit switch. If so, does anyone know which terminals control up versus down on a single solenoid or at the very least on the trim pump itself?

I am positive that I have the 12V power and the ground wires connected properly, as well as the 3-prong plug that can't be inserted wrong, so it's really a matter of just the trim-limit wires.

 

[boatguya1]

Re: Jumpering Trim Pump

The trim limit is not a player in the down circuit on any of the merc systems I'm aware of. If the motor was dead it would do what you say. The click is the sol for up, no sol for down so no click. The wire to the motor should be green or blue. Green down blue up, just jump 12v+ to them and the motor should run.

James

 

[boatguya1]

Re: Jumpering Trim Pump

Also there may be a switch by you shift bracket that, I think, only stops you from going up when you are not in neutral or forward. Pretty sure it's to stop you from blowing out the reverse lockdown. This is an older system than I normally work with. Don't jumper the trim motor if the shift bracket is in reverse to avoid damage to the reverse lock down.

James

 

[haulnazz15]

Re: Jumpering Trim Pump

Those are excellent responses. The throttle is currently in fwd right now as we just reinstalled the outdrive. I don't get the solonoid "click" except when both up buttons are pressed, otherwise I get silence from the down or up button when they are pressed. I can't imagine that the motor would be dead as it was in perfect order when we started the transom rebuild (although it's possible, just unlikely).

What would happen if the hydraulic lines were reversed? Also, per the Seloc manual, the "down" low-pressure side of the hydraulic lines should be gray. however, on my boat, both hydraulic lines were exactly the same (one goes to the trim sender on the transom bracket, the other goes to the trim pump). Will this do any damage if run that way? Will I know it's wrong by the fact that the trim isn't working (assuming I get the pump wiring solved)?

Thanks for the quick replies BTW.

 

[boatguya1]

Re: Jumpering Trim Pump

I'm not sure enough on the plumbing to say. I can vagely picture it in my head. I think what I was describing above is one generation newer than what your working on. I'm kind of picturing a sender/limit inside the boat above the steering, but I don't know enough about that one to be sure.

James

 

[haulnazz15]

Re: Jumpering Trim Pump

That is how it is setup, the trim sender is above the steering rack.