Trim will go up but not down

[Blentz17]

Alright, I need some help with this trim pump on my 1993 Gulfstream (Merc 3.7 Alpha 1 Gen 1). Over the weekend, I replaced the carpet in my boat so I had to remove all of the side panels and move some of the harnesses out of the way which included unhooking the harness to my trim pump. Long story short, I installed the carpet and rehooked up my trim pump and now it will trim up, but not down. When I push the button up on the throttle the outdrive comes up with no problem, but when i push it down, nothing happens and no sounds are coming from the solenoid. I thought a wire may have come loose so I checked the entire harness and everything seems to be connected correctly. I then went to the pump and arched the solenoid and the motor was trimmed down with no problem.

It seems that since the solenoid works when arched with a screwdriver, the solenoid is fine, I think there may be a power issue somewhere but with everything being connected as it should be I'm at a loss. Any advice? I have attached a picture of the pump I have for reference

 

[04fxdwgi25]

Bad tilt limit switch (left side of drive) would be my 1st place to troubleshoot. Jumper it out inside the boat and see if everything works.

 

[dubs283]

Bad tilt limit switch (left side of drive) would be my 1st place to troubleshoot.

Trim limit switch is part of the "up/out" circuit. It has no affect on the "down/in" circuit.

OP: when you jumped the solenoid with a screwdriver was it on the primary (small) post or across the secondary (big) posts?

 

[Bt Doctur]

check the 3 conductor plug, sounds like a poor/corroded connection

 

[Blentz17]

check the 3 conductor plug, sounds like a poor/corroded connection

Checked the harness with a test light, I'm getting power to the whole harness. Took the connector off cleaned it and nothing

 

[crazy charlie]

Try the switch on the shifter as you shift from fwd to neutral and reverse, Worth trying to change the positions as the issue may be in the switch.Charlie

 

[Blentz17]

Try the switch on the shifter as you shift from fwd to neutral and reverse, Worth trying to change the positions as the issue may be in the switch.Charlie

 

[Blentz17]

I just ran some test the pushed the shifter forward, neutral, and reverse and for a split second the motor trimmed down from the switch but it stopped after about 1 seconds and nothing again.

I did some further diagnostics with the test light on the solenoids the top one is fine when I push the trim button up I'm getting power to the big bolt on the top solenoid so i know the top is good. When I put the light tester on the top bolt of the bottom solenoid I'm getting power without touching anything with I think is normal. When I touch the light to the smaller bolt on the bottom solenoid thay the green wire connects to and press the trim button down I'm getting nothing.

Does this mean the bottom solenoid is bad?

 

[H20Rat]

The wire is rubbed through in your shifter. The fact it moved for a second rules out the solenoid. I've had the exact same thing happen on mine, its an easy fix if you pull the shifter handle apart.

 

[Blentz17]

The wire is rubbed through in your shifter. The fact it moved for a second rules out the solenoid. I've had the exact same thing happen on mine, its an easy fix if you pull the shifter handle apart.

So was the copper inside the wire exposed and grounding out somewhere inside of the shifter?

 

[JonBoat55]

I had the same issue, @H20Rat is correct. My wire was rubbing against a screw head around the shifter area and was grounding out depending on the adjustment of the throttle. It had stripped the coating away and was bare copper in one spot. Easy fix.

 

[Blentz17]

Ok, so I pulled the throttle apart this weekend and none of the wires appeared to be damaged. While I had the throttle open, I checked and was getting power to each wire. When i pressed the trim button down I was getting power to the green wire and the same when I pressed the button up for the blue. I went all the was down the harness and checked each point where the harness was spliced together and confirmed that there was power.

When I got to the harness, I confirmed that I was getting power at the plug. I again checked the solenoids, when I trimmed up, I was getting power to the top bolt of the top solenoid, moving down, i was getting power to the small bolt on the top solenoid and the top bolt of the bottom solenoid. When I checked for power to the bottom bolt of the bottom solenoid, no power. I checked all of the wires on the pump and on/around the solenoids and they seem to be in good condition.

I suspect the bottom trim solenoid is bad, however, when i arch the bottom bolt of the bottom solenoid with the top bolt of the bottom solenoid, it trims down with no issue. This leads me to believe that the solenoid is not bad... but then again Idk, i feel like I've eliminated everything else.

I then thought maybe it was a trim/limit switch problem, which should have anything to do with the up/down function of the trim motor, so i unplugged it, the same issue.

Thoughts..........

 

[dubs283]

I suspect the bottom trim solenoid is bad, however, when i arch the bottom bolt of the bottom solenoid with the top bolt of the bottom solenoid, it trims down with no issue. This leads me to believe that the solenoid is not bad... but then again Idk, i feel like I've eliminated everything else.

I then thought maybe it was a trim/limit switch problem, which should have anything to do with the up/down function of the trim motor, so i unplugged it, the same issue.

See post #3

 

[Blentz17]

See post #3

I saw post three, are you saying my issue could be related to the trim limit?

 

[dubs283]

are you saying my issue could be related to the trim limit?

No. The trim limit switch is not part of the down circuit

You should be testing for voltage at the primary (small post) side of the solenoid when engaging the down portion of the trim switch at the remote handle. If you have 12+ volts there and the solenoid does not engage then the solenoid is bad

The way you word it makes it sound as you are connecting the secondary (large) posts which would be bypassing the solenoid completely