Trim down, won't come up

[Bwana Don]

I have a;
1971 Starcraft
140 (3.0 mercruiser)
Merc 1 outdrive

Trim limit is checking open.
3 button trim switch is erratic (works if you push real hard).

I removed the limit switch and trim switch by using a toggle switch (return to neutral). I wired the red wire to the middle, the blue wire to the up, and the green wire to the down on the toggle. Threw out my trim gage too.

I push up on the toggle and the pump turns on but the outdrive won't budge. Push down (green) and nothing at all.

There is a switch going to the pump from the shifter linkage? It has blue wires going to it and is some kind of safety switch I think.

Questions;
Why won't the drive go up?
Why won't the drive go down?
What does the safety switch do? Will it cause the outdrive to lock down.

 

[Bondo]

Re: Trim down, won't come up

I push up on the toggle and the pump turns on but the outdrive won't budge. Push down (green) and nothing at all.

Ayuh,.... Is there any Oil in it,..??
If the motor ain't turnin', it's either Not gettin' Power, or it's Beat...

Manual #1, in the Adults Only section, I believe covers this...

 

[Bwana Don]

Re: Trim down, won't come up

Fluid full, to bottom of threads on screw. Manual downloaded.

Before I trim it, I can move the outdrive up by hand. Once I try to raise it then I can't budge it. It's lock down. Pump spins at first, then labors heavy.

I'm afraid to ask this but, what's a reverse lock valve? I just ran across it in the service manual.

I'm not worried about no power down (green), I think that's the solenoid or corroded connections. This not coming up while under pressure has me stymied.

 

[RRitt]

Re: Trim down, won't come up

If the motor spins but the system does not lift then there are only three things left.

1) the pump is not putting out adequate fluid pressure
2) the piston is not holding pressure
3) there is no where for backside fluid to escape

1 and 3 are usually problems with pump valves. 2 is fairly rare unless your boat is very old or has gotten water in the fluid.

 

[Bwana Don]

Re: Trim down, won't come up

Previous owner replaced some hydraulic lines, before he passes away. I wonder if they mixed the up and down lines.

1) I'll pull the cylinders off and extend them halfway. See which way they move.

2) Pull the pump and nose around. Pressure should be 2500 - 3500 PSI, I'll check that.

3) Reverse lockout valve has a switch (electrical) should read infinity when open and continuity when closed. I don't fully understand this feature at the moment. I'll read more and do the electrical checks.

I read that Alpha One trim pumps have the lock out feature built into them. Has anyone upgraded to Alpha One or A1 Gen II, trim pump? What is involved?

 

[Bondo]

Re: Trim down, won't come up

What is involved?

Ayuh,... Pull your pump,+ the reverse lock off,+ install the new pump,+ the new return line....

The reverse lock keeps the prop in the water, when backing...

 

[Bwana Don]

Re: Trim down, won't come up

Uhmm, how do I say this without sounding dumb? I don't think there is a way. So here goes.

The toggle switch and pump work just fine. Blue is down and pushes the the outdrive down. I had the switch reversed in my mind. Up on the switch energizes the middle and bottom legs of the circuit, not the top and middle.:redface:

Jumped the solenoid and trim goes up, the switch trims it down. Half of the solenoid doesn't work. I need a new one.

My neighbor who is an auto mechanic figured it out for me. It cost me two beers, and was well worth it. Thanks Chris.

Thanks to all here.