Tilt & Trim problems

[bevdan]

I recently acquired a 85 Mercury 150 Black Max. The tilt and trim is working intermittently. Sometimes the relays will just click and nothing happens and sometimes the motor will run and nothing happens up or down. When I put power directly to the motor it will go up or down according to which wire I put power to but only for a few seconds. Sometimes it will cycle all the way up and down before cutting out. Other times only run for a few seconds. Any ideas to what's going on? Thanks in advance for any help!!!

 

[Chris1956]

Well, first clean all the electrical connections. Since the motor only often spins for a few seconds, it makes sense to clean it up and test the components. You may have a bad winding, or simply bad brushes.

If that doesn't fix it, you need to look further. That motor should have solenoids. When the primary winding is energized the solenoid should connect the secondary winding. That can be tested for function and resistance.

 

[sam am I]

sometimes the motor will run and nothing happens up or down

When I put power directly to the motor it will go up or down according to which wire I put power to but only for a few seconds

After those "few seconds" is the trim/pump motor continuing to run tho?

If so, and given these ^^^ two symptoms, I'd say fluid check, air bleed.

Also, I recall something about the plastic manual pressure release screw end tip breaking off on some units that makes them crap the sheets, not sure it relates to yours but, might double check on that.

Sometimes the relays will just click and nothing happens

This sounds relay contacts and/or brushes/connections as chris has pointed out

 

[bevdan]

If that doesn't fix it, you need to look further. That motor should have solenoids. When the primary winding is energized the solenoid should connect the secondary winding. That can be tested for function and resistance.

It does have solenoids, but it does this with it running straight to battery bypassing the solenoids.

 

[bevdan]

Is that a one piece motor and pump? Kind of confusing looking at a diagram.

 

[Chris1956]

OK clean up all electrical connections, and jumper the motor directly from the battery. If the motor still runs for a few seconds only, see if you can disassemble and clean and test the motor components.

 

[bevdan]

Ok, so I finally got around to working on this and it turns out to be the motor. I ordered one of the replacement 2 wire 99186t replacement motors from Amazon and it appears the bracket that mounts the motor to the pump and to the housing is a little different. It will still all bolt up just the pump sits in a different position in the housing.

My question is does it matter? To me it don't seem to but I'm no expert

 

[Chris1956]

Gee, I would think (not sure) that an '85 Merc would use a 3 wire PTT motor. You might verify.

 

[bevdan]

It did but this is one is suppose to replace it and the selenoids with relays

 

[Chris1956]

OK, as long as you know you need to rewire it and use relays, you should be fine. I didn't want any surprises (for you).

 

[bevdan]

It came with the new relays and wiring. I was just concerned about the position of the pump in the housing.

 

[bevdan]

Got it all put back together and it works like a charm. Thanks for the replies and advice.

Good to know there are still people willing to help others!