How to know when a power trim motor needs to be replaced?

When boaters encounter problems with their trim engines, the first step is to diagnose the cause of the problem. You will need to determine if it is the electric trim motor that remotely controls the tilt of the outboard motor, or the hydraulic pump or the 12 volt power system causing the problem.

Start by confirming that your trim motor is powered and that you have enough power for the trim motor to function properly. Check the battery voltage and the connections of all electrical wires.

All trim motors use a 12 V current reverser with a blue wire and a green wire. The blue wire raises the trim when powered, while the green lowers it. Some systems also have a black wire, which works as ground on units that are not grounded through the housing.

To diagnose a trim motor problem, use a battery to directly apply a 12-volt voltage to the blue wire and then to the green wire, which should cause the trim to go up or down, respectively. Test it in both directions. If the engine is running, the problem is probably related upstream to the trim relay or a problem with the trim switch.


If the trim motor fails during the diagnostic procedure, then it must be replaced.

If the engine is not in the high position, use the bleed screw to raise it.

Once the motor is in the high position, simply disconnect the cables from the trim motor on the harness at the level of the relay (s). Then unscrew the 4 screws that hold the trim motor on its base. Once you have uninstalled the faulty trim motor, grease the new trim motor to reinforce protect it from corrosion, and possibly use sealant type Sika 291i to perfect its tightness at the level of the plate and at the level of the entry of the wires. Connect the cables of the trim motor to the electrical harness, clean the joint surface then install the new O-ring supplied, and finally secure the motor to the trim with the screws. Gradually tighten crosswise.

We can provide you with the following trim motors:

Yamaha trim motor
Mercury trim motor
Mariner trim motor
Mercruiser trim motor
Honda trim motor
Suzuki trim motor
Johnson Evinrude trim motor
Tohatsu trim motor
Volvo Penta trim motor