Where to begin... OMC Stringer Trim (NOT TILT)

[DukesFin]

I've got an '74 model OMC 165 Stringer outdrive and a GM L6 250cid motor with the trim motor mounted to the front motor mount...

My trim gauge has never worked (when trimming, the gauge either bottoms out or did not move at all, but it DID trim up and down with no problems.

Now, it won't trim up or down. When I hit the switch, I can hear a "click", but that is all.

While I was working on the motor, I had the battery out, so I grounded the battery to the engine block and ran a hot wire to both the "up" and "down" leads on the solenoids (where the up and down wires are connected from the trim motor). When I did this, the motor did run, but when touching the hot wire to the leads, it sparked pretty good right when it touched, but DID operate the trim both up and down. Not for long though. On it's way down, it just quit. I think my battery was low enough for this to be the cause of the motor only running a few seconds though.

Where do I begin troubleshooting the trim system?

Thanks!

 

[wire2]

Re: Where to begin... OMC Stringer Trim (NOT TILT)

The gauge is operated from a sender, which will be a potentiometer, (like a sound volume control), with an arm that moves when trim is operated.
One wire is grounded, the other goes to the sender terminal of the gauge.

I don't have my OMC manual anymore, this is the motorized jack shaft system, right?

The dash or control lever in/out switch should operate the pilot (or coil) circuit of the solenoids, which is the smaller wire & terminal. There should be a 12 v,(red wire) on 1 large terminal, the other large terminal will be in or out, (usually blue/white & green/white leads to the pump. A 3rd black wire from the pump is ground.

 

[OMCboater]

Re: Where to begin... OMC Stringer Trim (NOT TILT)

I recently got my much neglected (by previous owner) tilt and trim motors working on my 69 OMC 120 just by cleaning them up. the sparking when you touch the hot to the leads is normal - they pull a lot of current. I would suggest first of all giving it a couple of hits with a small piece of 2x4. If it works better (for a short time) then it is highly likely that you just need new brushes. If that doesn't make it work better then you better remove it and open it up anyway to see what is up.

 

[oh-u812?]

Re: Where to begin... OMC Stringer Trim (NOT TILT)

I replaced mine last year. It was about $200. You might make sure you getting power to the motor. If you are, I'd take it off (pretty easy to get to) and inspect it. If it's not too far gone, you may find an electrical shop that'll rebuild it for you.