GM Service Manual Online
For 1990-2009 cars only

Voltage to the radio is available at all times through the CKT 1140 (ORN) wire. CKT 1140 (ORN) provides voltage for the following activities:

    • Radio station memory storage
    • Clock memory

With the ignition switch in ACC or RUN, voltage is supplied to the radio through the RADIO Fuse and the CKT 43 (YEL) wire. Each speaker has its own pair of leads. The radio/clock display brightness is at full intensity with the ignition switch in ACC or RUN. Voltage for the radio/clock display is supplied by the CKT 43 (YEL) wire. The radio illumination bulb voltage is supplied by the CKT 8 (GRY) wire.