GM Service Manual Online
For 1990-2009 cars only

The power seat switch is supplied battery positive voltage from the POWER SEAT 25A circuit breaker through circuit 540. The switch is grounded through circuit 550. Each adjuster motor is controlled by two switches connected through the adjuster motor supply circuits. The seat adjuster switches are closed to ground when inactive. When an adjuster switch is pressed from an inactive position to an active position the switch contact is moved from ground to battery positive voltage while the inactive switch provides the ground. The direction of the adjuster motor rotation is determined by which supply circuit is battery positive and which is ground.