Seat Motors - Diagnostic Guide
How to determine if you need a new seat motor, and if so, which one needs replacing?
We've posted this useful guide for Dodge Ram trucks but in fact, the information can be applied to most cars and trucks. This information is courtesy of Two Men One Garage, the power seat repair parts folks who make replacement seat motors for most makes and models so we don't have to resort to going through the dealer and/or replacing entire units. You can find them here: Power Seat Repair Parts | Two Men One Garage | United States
We hope you'll find this a handy guide to determine your next move.
Always make sure your switch is good before assuming the motor is bad. To check the motor, you can connect a good 12v power source and ground to the motor contacts.
Don't worry about getting the wires backwards and damaging the motor. The switch just changes the direction of current through the motor, which changes the direction of rotation.
Check to make sure the switch is getting 12v. Use a multimeter or test light. If 12v is not present, check for a blown fuse.
COMMON SYMPTOMS
A. FORWARD/BACKWARD MOVEMENT PROBLEMS
1. The seat moves forward with help or it moves erratically.
The forward/backward gear assemblies are stripped or have broken teeth.
In both cases, gear assemblies should be replaced.
2. The seat doesn’t move at all, but the truck seat motor runs.
The forward/backward gear assemblies are stripped or have broken teeth.
Replace the gear assemblies.
3. The seat doesn’t move at all and the truck seat motor doesn’t run.
Assuming you have power to the truck seat motor from the switch assembly and the connector
is making good contact with the motor, then the motor is most likely bad. Replace the truck seat motor.
4. The seat starts to move then stops. The motor cannot be heard running.
(1). If the forward/backward gears have a broken tooth, the motor will try to rotate them until the broken tooth binds up the gear case. The motor will then overheat and stop working. Replace the gears.
(2). The motor could be worn out, overheats and trips the internal thermal breakers. Once it cools down it will attempt to run again. If this is the case, the motor probably needs replaced. Another problem could be excess drag or binding from the seat. Loose coins or trash could be binding up the seat, causing the motor to overheat. Make sure the track is free of obstructions.
B. UP/DOWN MOVEMENT PROBLEMS
1. The truck seat starts to move up or down, then stops.
The car seat motor is weak or the gears are binding, which causes the thermal breaker to trip.
Replace the truck seat motor/gear assembly.
2. The truck seat doesn’t move up or down, but the truck seat motor runs.
The up/down gears are stripped or have broken teeth. Replace the motor/gear assembly.
3. The truck seat doesn’t move at all and the truck seat motor doesn’t run.
Assuming you have power to the truck seat motor from the switch assembly, the motor is burnt out.
Replace the truck seat motor/gear assembly.
NOTE: On six-way adjusting seats like in the Dodge Ram truck, the up/down movement is controlled by the front tilt and rear tilt motors. If one of these tilt motors is bad, then the up/down will not work correctly. Use the above steps to isolate which tilt motor is bad.
