ker88839_ch15.qxd
1/9/06
11:36 AM
Page 329
Body Accessory Systems Operation
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Figure 15-24. The motor in this door can raise and lower the window. (GM Service and Parts Operations)
nected to one of the two motor brushes. The window is moved up or down by reversing the direction of motor rotation. Motor rotation is controlled by routing current into one brush or the other. Each individual window switch is connected in series with the driver’s master switch. Current from the motor must travel through the master switch to reach ground.
POWER SEATS Electrically adjustable seats can be designed to move in several ways, as follows: • Two-way systems move forward and back-
ward.
• Four-way systems move forward, back-
ward, and front edge up and down. • Six-way systems, used in most late-model
applications, move the entire seat forward, backward, up, and down; tilt the upper cushion forward and backward, and move the lower cushion front edge up and down, and rear edge up and down. GM makes a typical two-way power seat system, as shown in Figure 15-26. The seriesconnected motor has two electromagnetic field windings that are wound in opposite directions. One winding receives current from the forward switch position. The second winding receives current from the rear switch position. Current through one winding will make the motor turn in
