Power Seat Inoperative

Power Seat Inoperative

Circuit/System Description

Power seat without memory is completely controlled through the seat adjuster switch. Battery voltage is supplied at all times to the seat adjuster switch from the PWR/SEAT 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.

Circuit/System Testing

1. Disconnect the harness connector at the seat adjuster switch.
2. Test for less than 1 ohm of resistance between the ground circuit terminal B and ground.

• If greater than 1 ohm, test the ground circuit for an open/high resistance.

3. Verify that a test lamp illuminates between the B+ circuit terminal and ground.

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

4. Connect the harness connector at the seat adjuster switch.
5. Disconnect the harness connector at the appropriate seat motor assembly.
6. Connect a test lamp between the motor control circuit terminals of the inoperative motor.
7. Verify that the test lamp illuminates while pressing the appropriate seat switch in both directions.

• If the test lamp does not illuminate for both directions, test the motor circuits for a short to ground or an open/high resistance. If the circuits test normal replace the seat adjuster switch.

8. If the circuits test normal replace the inoperative motor assembly.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

* Seat Switch Replacement - Power (Impala) Seat Switch Replacement - Power (Monte Carlo)
* Front Seat Adjuster Replacement (Impala) Front Seat Adjuster Replacement (Monte Carlo)
* Power Recliner Motor Replacement - Front Seat Verification Tests