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Trim Motor

zumbadora

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"I have a V8 mercruiser with a

"I have a V8 mercruiser with a bravo 3, this board has helped me for the past 6 years, thanks to everyone.
My trim motor started to play funny with the switch to lower the drive and taking apart this every thing looked good, then I went to the motor trying to bypass the switch and nothing maybe I am doing this wrong? Is there a way to try the motor or to rebuild it, also I was froward a web site for parts that I used last year but I lost the info it was affordable and fast.
Thanks again. Hector"
 
"There are 2 large HIGH AMPERA

"There are 2 large HIGH AMPERAGE!!! solenoids at the trim pump assy. One is for up and the other down. Jump the 2 large terminals on top of one solenoid together for a moment. If the pump runs try the other. If one of them does not run the pump; you found the problem. If both work, the trouble may be in you trim switch assy."
 
"I have 3 cables coming out a

"I have 3 cables coming out a green blue and black, also I was looking at the rebuilt kits how inexpensive they are compared to the new motor, brushes from $ 8 bucks, is it worth it or easy to rebuilt."
 
"Hector
As Guy states, find t


"Hector
As Guy states, find the problem first. The pump motors are quite robust. I would look at the switches and solenoids first.
Bert"
 
"Hector:

Have you proven th


"Hector:

Have you proven that the motor is defective? The solenoids are generally what fail before the motor. There is a 110 amp. fuse where the battery connects to the unit and voltage is passed to the solenoids by a brass buss bar. I have seen corrosion between the fuse connection and the buss bar. The B bar is connected between the two solenoids. The motor is connected on the other terminals of the solenoids. Sometimes the nut on the solenoid that is UNDER the buss bar will come loose and then the connection is loose. Are the brass studs of the solenoids blackened? If yes, that indicates alot of heat from high current caused by a burned contactor inside of the solenoid.

You can test the motor by using a 10 ga. jumper wire to each green and blue motor wire. Make sure the ground wires are CLEAN and tight. Let us know what you find.

How the trim/tilt works

Before you tear anything apart or replace wiring and switches, test it out; first by visual inspection by pulling back and forth on the wires while operating the switches and then test with a meter. At the commander switches, the red wire will always have 12 volts. The green wire gets 12 volts when the trim toggle is held down. The blue wire gets 12 volts only when the toggle is held up or the trailer switch is pushed in. The purple wire is part of the limit switch circuit.

If the switch voltages are as they are supposed to be then go to the trim/tilt pump assy. and make sure the purple wire connector (single wire) and the blue wire connector with two blue wires on one side of the connection are not corroded or loose. These are the trim position and limit switch wires. Pull them apart and inspect; they should be clean and tight; reconnect them. If necessary, trace the wires to the front of the engine near the slave solenoid. One wire is grounded near there and the other is connected to a terminal. If you don't get a voltage reading at the terminal junction, apply 12 VDC to see if the trim gauge moves. If it does, check for voltage back at the trim pump connections. If no voltage there, apply 12 VDC there to check gauge movement.

Next check the three wire connector (RED, BLUE & GREEN) at the pump assy. This plug can vibrate loose and cause your problem. Pull it off and see if the pins are clean and not corroded; reconnect it.

The RED wire in the plug sends 12 volts from the pump assy. to the toggle up/down and trailer up switches. The BLUE & GREEN wires bring 12 volts from the toggle trim/tilt and trailer switches to the two solenoids on the pump assy.

The GREEN wire goes to the DOWN solenoid while the BLUE wire goes to the UP solenoid.

Did you check the switches with an ohmmeter? The trim/tilt switch is a 2-way switch and will show continuity only when it is toggled in each direction between two of the wires.

Up toggle connects the RED wire to the BLUE wire. Down toggle connects the RED wire to the GREEN wire. The TRAILER UP switch also connects the RED wire to the BLUE wire.

The OD trim limit switch will only send voltage to the trim/tilt switch in the upward toggle position if the OD limit switch is below the adjusted trim limit that keeps the OD being out of the water.

To test the limit switch circuit, lower the OD to the down position and slowly raise it with the trim toggle up until it stops. Then measure the distance between the trim cylinder attaching bolts. If the distance is approx. 22 +/- 1/4 inches, then the trim limit switch is adjusted properly and the commander trim toggle switch is working in the up/down mode.

Go to the trim/tilt pump assy. and make sure the purple wire connector (single wire) and the blue wire connector two blue wires on one side of the connection are not corroded or loose. Pull them apart; they should be clean and tight; reconnect them.

Next check the three (RED, BLUE & GREEN) wire connector at the pump assy. The RED wire in the plug sends 12 volts from the pump assy. to the toggle up/down and trailer up switches. This plug can vibrate loose and cause your problem. Pull it off and see if the pins are clean and not corroded; reconnect it.

The BLUE & GREEN wires bring 12 volts from the switches to the two solenoids on the pump assy. The GREEN wire goes to the DOWN solenoid while the BLUE wire goes to the UP solenoid.

Disconnect the trim/tilt assy. wires from the battery and then check each of the nuts and studs on the solenoids for clean and tight fittings. Each solenoid has three wires and the buss bar connected to it. The bases of them have a black ground wire and a small blue wire to one and a small green wire to the other.

On top of each solenoid, the large BLUE wire from the pump motor attaches to a large copper stud with the solenoid that has the small blue wire at the base while the large GREEN wire from the pump motor attaches to a large copper stud with the solenoid that has the small green wire at the base.

The other copper solenoid studs are connected together with a copper buss bar. One of the two studs will also have a funny looking 110 amp fuse attached to the bar. The large RED wire from the battery connects to the 110 amp fuse. This large red wire is the power for this buss bar. A small RED wire attached to the bar stud sends 12 volts to the switches which in turn sends the 12 volts to the solenoids which turns on the pump motor.

Important: if the studs on the either solenoid are dark and not like a clean penny, especially the BLUE wired solenoid, this solenoid is failing due to age and/or a loose bottom copper stud nut. The dark color comes from heat generated inside of the solenoid by the contactor because it is arcing like welding similar to points wearing out. Change the solenoid.

Cleaning Trim Limit Switch & Trim Position Sender

For the trim/tilt problem you are experiencing, if the wires from the limit switch (port side) and trim position sender (starboard side) are in good condition, they (Switch or sender) can be disassembled to clean out the old hardened grease. SCRIBE the sides of each one and the OD for a reference mark before removal. Clean out the old grease and pump fresh Mercruiser 2-4-C grease thru the zerk fittings before reinstallation. Clean the small brass contact points with solvent and a pencil eraser until shiny; repack w/ 2-4-C grease and reinstall by aligning reference marks."
 
"Yeah i bought my boat and the

"Yeah i bought my boat and the guy said the pump was bad in it. He had the pump so i replaced it, still didnt fix the problem. My switch panel was messed up and it had some bad hydraulic lines. The pumps are expensive compared to fixing those. So test the wiring and stuff first. If you are not sure of the switches they are easy to check with a multimeter. Switch the multimeter to resistance and remove power to the switches. Put the leads accross the switch and press the button if the meter goes to 0 then they are good. If you want to check the wiring harness going back you can do it like this. Remove power find the blue wire and put one lead up front one in the back and see if it goes to 0. You can use a piece of wire to make the leads long enough. Repeat this with the green and purple wires. The reading of resistance is as follows. O is continuiity you have complete line no breaks. 1 or what your meter reads when the leads are not connected and on is Open no contact. Any reading in between is a measurement of resistance in Ohms. Sorry if this is to much info, use to be an electronic nut."
 
"I took the motor assembly off

"I took the motor assembly off and tested the motor, as the recommendation from this great forum it works fine. Bypassing the solenoids it pumps up and down very good, going true the solenoids only up works,my question is do they sell the silenoids seperate? Shoud I replace both?
Thank a million, Hector."
 
"I could not find the curved b

"I could not find the curved bracket one, on page 600 the model # 18-6768 at the top left side is the exact one that I have and you are right a spare can get me out of trouble at any time needed on the water or on land."
 
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