The power seat is controlled through the seat adjuster switch. Battery voltage is supplied at all times to the seat adjuster switch from the PWR SEATS 25A circuit breaker that is located in the I/P fuse block. When the seat adjuster switches are in an inactive state, the switch contacts are closed to the switch ground circuit.

All seat motors are reversible. For example, when the seat horizontal forward switch is pressed to move the entire seat forward, battery voltage is applied through the switch contacts and the seat horizontal motor forward control circuit to the motor. The motor is grounded through the horizontal motor rearward switch contacts and the horizontal motor rearward control circuit to the motor. The motor runs in order to drive the entire seat forward until the switch is released. Moving the entire seat rearward works similarly to moving the entire seat forward, except that battery positive voltage and ground are applied on opposite circuits causing the motor to run in the opposite direction. All seat motors are powered this way.

Schematic Reference

Driver Seat Schematics

Connector End View Reference

Power Seat Connector End Views

Electrical Information Reference

1. Operate the switches for the seat directional motors listed below in both directions. The seat should move in the commanded directions.

•	Horizontal Motor

•	Front Vertical Motor

•	Rear Vertical Motor

⇒	If the power seat is inoperative in all directions, refer to the Seat Adjuster Switch Circuit Test.

⇒	If the seat front or rear vertical adjuster motor is inoperative, refer to the Seat Vertical Motor Circuit Test.

⇒	If the seat horizontal motor is inoperative, refer to the Seat Horizontal Motor Circuit Test.

Seat Adjuster Switch Circuit Test

1. Ignition OFF, disconnect the harness connector at the seat adjuster switch.
2. Test for less than 5 ohms between the ground circuit terminal G and ground.

⇒	If greater than the specified range, test the ground circuit for an open/high resistance.

3. Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal A and ground.

⇒	If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.

4. If all circuits test normal, test or replace the seat adjuster switch.

Seat Vertical Motor Circuit Test

1. Ignition OFF, disconnect the harness connector at the appropriate seat vertical motor.
2. Test for less than 5 ohms between the control circuit terminal 1 and ground.

⇒	If greater than the specified range, test the control circuit for an open/high resistance. If the circuit tests normal, test or replace the seat adjuster switch.

3. Test for less than 5 ohms between the control circuit terminal 2 and ground.

⇒	If greater than the specified range, test the control circuit for an open/high resistance. If the circuit tests normal, test or replace the seat adjuster switch.

4. Connect a test lamp between control circuit terminal 1 and control circuit terminal 2.
5. Ignition ON, command the seat motor in the UP and DOWN directions using the seat adjuster switch. The test lamp should turn ON when commanding the UP and DOWN states.

⇒	If the test lamp remains OFF for either of the commands, test the control circuits for a short to ground. If the circuits test normal, test or replace the seat adjuster switch.

6. If all circuits tests normal, test or replace the seat vertical motor.

Seat Horizontal Motor Circuit Test

1. Ignition OFF, disconnect the harness connector at the seat adjuster switch.

Important: When performing the following tests, make sure that the seat is not all ready in the position the test is attempting to produce.

2. Install a 30A fused jumper wire between the control terminal B and 12 volts. Momentarily install a jumper wire between the control terminal C and ground. The seat horizontal motor should momentarily perform the FORWARD function.

⇒	If the function does not perform as specified, replace the seat horizontal motor.

3. Reverse the polarity of jumper wires; the a seat horizontal motor should perform the REARWARD function.

⇒	If the function does not perform as specified, replace the horizontal seat motor.

4. If all circuits test normal, test or replace the seat adjuster switch.

Driver Seat Adjuster Switch

1. Ignition OFF, disconnect the harness connector at the driver seat adjuster switch.
2. Test for infinite resistance between the control terminals listed below and the B+ terminal A with the switch in the open position.

•	Seat horizontal forward terminal B

•	Seat horizontal rearward terminal C

•	Seat front vertical up terminal D

•	Seat front vertical down terminal E

•	Seat rear vertical up terminal H

•	Seat rear vertical down terminal F

⇒	If not the specified value, replace the driver seat adjuster switch.

3. Test for less than 2 ohms between the control terminals listed below and the B+ terminal A with the switch in the closed position.

•	Seat horizontal forward terminal B

•	Seat horizontal rearward terminal C

•	Seat front vertical up terminal D

•	Seat front vertical down terminal E

•	Seat rear vertical up terminal H

•	Seat rear vertical down terminal F

⇒	If greater than the specified range, replace the driver seat adjuster switch.

4. Test for less than 2 ohms between control terminals listed below and the ground terminal G with the switch in the open position.

•	Seat horizontal forward terminal B

•	Seat horizontal rearward terminal C

•	Seat front vertical up terminal D

•	Seat front vertical down terminal E

•	Seat rear vertical up terminal H

•	Seat rear vertical down terminal F

⇒	If greater than the specified range, replace the driver seat adjuster switch.

Seat Vertical Motor

1. Ignition OFF, disconnect the harness connector at the appropriate seat motor.

Important: When performing the following tests, make sure that the seat is not all ready in the position the test is attempting to produce.

2. Install a 30A fused jumper wire between the control terminal 1 and 12 volts. Momentarily install a jumper wire between the control terminal 2 and ground. The seat vertical motor should momentarily perform the UP function.

⇒	If the function does not perform as specified, replace the seat vertical motor.

3. Reverse the polarity of jumper wires; the a seat vertical motor should perform the DOWN function.

⇒	If the function does not perform as specified, replace the seat vertical motor.

Seat Horizontal Motor

1. Ignition OFF, disconnect the harness connector at the seat adjuster switch.

Important: When performing the following tests, make sure that the seat is not all ready in the position the test is attempting to produce.

2. Install a 30A fused jumper wire between the control terminal B and 12 volts. Momentarily install a jumper wire between the control terminal C and ground. The seat horizontal motor should momentarily perform the FORWARD function.

⇒	If the function does not perform as specified, replace the seat horizontal motor.

3. Reverse the polarity of jumper wires; the a seat horizontal motor should perform the REARWARD function.

⇒	If the function does not perform as specified, replace the horizontal seat motor.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.