TOPIC: Mercury Power Trim and Tilt Question

I recently acquired and older 70 hp mercury outboard. I can raise the motor with the power trim, but it won't work to lower it. Any suggestions on a possible fix?

Thanks

Tate there any sounds what so ever when you hit the down switch, such as clicking? If not, it's either an issue with the switch or wiring between the switch and motor. If there is a clicking, it's a problem with the motor.

Thanks Brain. There isn't any sound when I hit the switch. I'll check the switch and the wiring.

Don

It could be a bad solinoid on the motor for the trim. Try a jumper from the hot wire to the nearest small wire on the solinoid and see if it works then. If it does, it is the solinoid.
Bill

If the trim pump is in the boat, there are (3) wires coming out of the trim motor.
The Black is ground (-)
The Blue is UP when jumped to 12vdc (+)
The Green is DOWN when jumped to 12vdc (+)

If the trim pump works for UP, but not DOWN,...Odds are it is a dirty or corroded wire connection issue - OR - if there are (2) solenoids (one for UP & one for DOWN,...It could be the solenoid.

Connect the larger Black wire coming directly out of the trim motor to a good Battery (-) Negative.
Then using a jumper wire - touch the larger Green wire coming out of the trim motor to a good Battery (+) Positive.
The trim motor should run in reverse & lower the Merc down.
Not all of this generation of trim motors had (2) solenoids. Many had just (1) for UP, and for DOWN the Green wire went direct to the trim switch without a solenoid since DOWN typically doesn't create the load that UP does.
doc

If you have only (2) wires coming out of the trim motor - don't proceed until how to test is explained.

I just been messing my Merc and was getting up, but no down also. Simple loosen the wires and rotate to scrub a bit.. tighten and try it. Worked for me. Heres a pic Doc sent me long ago. You have the same pump?

Remember blue is up and green is down. If you forget.... remember lawn is green = down, Sky is blue = up. Make sure you have a good rocker switch, power, and a ground.

bump
Back To The Top (BTTT)

The reverse lockout knurled knob on the power trim pump is used to allow the motor to be raised manually. To do this you would turn the knob full clockwise to release the locking function.

Unfortunately, this only lets you raise the motor, starting from the "down" position. You can't lower the motor without disconnecting a hydraulic line, or pulling one of of the allen-socket "bleed" port screws on the PT&T cylinders which will also relieve oil pressure.

Note that if the pump and controls are working properly, you have to have the reverse lockout knob all the way CCW for normal operation.

If the "down" switch isn't working properly, you could always try jumping the down solenoid. If you think the solenoid is shot, you could swap them out and see what happens.

HTH & let us know what you find.......ed

Thanks Ed for all that information. You guys are great, so knowledgeable and willing to share information. I have to leave town for awhile, but when I get back I'll try what you said and let you know how it worked out. Thanks again.
Don

Thanks again Ed. I jumped the down solenoid and it lowered the motor.

Don

If you have the old-style 3-button power T&T switch on the dash, with rubber covers, lots of times the contacts inside are just dirty. These switches are the same construction as the pushbutton kill switches on the little Twin Mercs.

If you take the switch assy out and apart, you can burnish the round disc-type contact that is fastened to the rubber pushbutton. And clean/polish the 2 little pointy brass contacts that are shorted by the the disc contact.

Once nice 'n clean, they'll work like new. The fact that the down solenoid worked locally leads me to believe the switch assy is the problem. Or a bad wire in-between, but more likely dirty switch(es).