Trim Up works, Trim Down doesn't click or do anything - 1990 Mercury 175 XRi

[JMO1]

Same symptom if I use the trim button on the motor, the button on the the throttle at the console, or the trim button at the bow.

The trim up work fines, trim down button in all 3 locations doesn't click or do anything.

I see 3 wires coming from the switch at the motor trim button, 1 Light Blue, 1 Green, and 1 Red Wire.

I'm thinking it has to be a wiring connection issue, since all 3 buttons don't work, and the trim up works fine.

If you can confirm how to troubleshoot and fix this, that would be appreciated.


Thanks,
Jon

 

[alldodge]

Red supply's power for all trim functions
Blue is trim up
Green is trim down

Check the relay with the green wire attached. Can swap relays to see if its a bad relay

 

[JMO1]

Thanks AllDodge,

I disconnected the Blue and Green wires on the trim switch, and then connected this switch's Green wires to connect to the Blue wire coming from the motor, and now the Trim Down switch is activating the Trim Up function, that tells me the switch itself is on the problem, correct?

I'm new to doing this type of work, so I don't know exactly where the relay is and how many wires I will have to disconnect to replace.

 

[alldodge]

Before only trim up, no down
swap the wires at the relays (up is down and down is up) and only the trim up works when pushing down.
This would tell me the down relay is bad.

Reason being, is no mater how its wired, only the up works

A second test, is the green wire was on the bottom relay. Take a jumper wire and jump from the red wire on the trim to the small terminal the green wire came off if. If nothing happens the relay is bad, or the ground going to the relay coil is not connected or broke

 

[JMO1]

I need to correct one thing I said before, see the first image here, I have the Green wire hooked to the Blue wire and the other end still connected to the Green wire. With this connection, the Trim Down button trims the motor up, and the Trim Up button does nothing since I have the Blue wires disconnected.

If I connect to the Blue wire on the left instead of the Green wire I have connected, the Trim Up constantly runs, whether I push the Trim button or not.

I followed the Green wire and the power wire to the top of the motor, is that where the relays are (2nd image)?

If I tried to follow the other end of the Trim wires, however they go through a plastic adapter and then the colors change on the backside of that adapter, so I have no idea where the Green or Blue Wires go in regards to where a lot of the wires are connected to the side of the engine block circuitry.


Thanks,
Jon

 

[alldodge]

Sorry.............but ........... I really don't know what to say

Please put everything back like it was

Follow the Green/White (small wire) from the shifter all the way to the relay

Follow the Blue/White (small wire) from the shifter all the way to the other relay (note it should not go to the same relay)

Swap those 2 wires and see if it works opposite, or if it stays with only UP function working

 

[JMO1]

I was able to follow the Green wire to the back of the motor to the Solenoid, I traded positions of the two trim wires coming from the switch, and then the Trim Down button trims the motor up and the Trim Up button does nothing.

I removed the Solenoid that the Green wires connect to and the part number is 8996158.

My plan is to buy one of these at NAPA and hope that is the culprit of the Trim Up button not engaging the trim motor.


Thanks again,
Jon

 

[JMO1]

The last sentence should be:

My plan is to buy one of these at NAPA and hope that is the culprit of the Trim Down button not engaging the trim motor.

 

[alldodge]

Sounds like a good plan

 

[JMO1]

I was able to replace the Trim Down solenoid, part number 8996158 and now Trim Down is working fine. Thanks for the tips guys!

A few things to be aware of if you try this for the first time like I did.

When I took the solenoid bolts off, 2 of them, I was assuming they were threaded into the based plate they connect to. When I went to install the replacement, it became apparent these bolts had a nut on the backside of the plate. I lucked out and the 2 nuts were still sitting below the base plate from when I removed the old solenoid, so I was able to reuse those. I had to use a vice grip to hold these nuts in place below the plate since there isn't enough room to get your hand underneath that plate. I disconnected the base plate's 4 bolts, however the spark plug wires prevent you from getting much room behind the plate, so I used the vice grip to hold the nut in place to receive the bolts. Also, the 4 bolts for the base plate have spacers on the backside that you need to keep track of and re-align when you re-attach the base plate.