GM Service Manual Online
For 1990-2009 cars only

The right IP fuse block RAC/TRUNK REL fuse provides battery positive voltage to the power antenna relay on CKT 1540 (ORN). When the radio is turned on, voltage is applied to the power antenna relay coil on CKT 145 (DK GRN). The antenna relay contacts close and voltage is supplied to the antenna motor. The other motor circuit is grounded through the antenna motor up limit switch and the power antenna relay contacts. The motor drives the antenna mast up. At the end of travel, the up limit switch opens and the motor stops. When the radio or ignition switch is turned OFF, voltage is removed from the power antenna relay coil. The contacts open, applying battery voltage to Pin C of the power antenna. Pin B is grounded. The motor drives the antenna mast down. The down limit switch opens at the end of the antenna mast travel, turning the motor off.