Radio
| • | Voltage to the radio is available at all times through CKT 1140
(ORN). |
| • | CKT 1140 provides voltage for radio station memory storage
and for the clock memory. |
| • | With the ignition switch in ACC or RUN, voltage is supplied to
the radio through the RADIO fuse and CKT 43 (YEL). |
| • | 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. |
| | The voltage is supplied by CKT 43 (YEL). |
| • | When the parklamps or headlamps are turned ON, voltage is supplied
to the radio through CKT 1382 (PPL/WHT). |
| • | When the radio senses the signal, the radio switches voltage for
the display from CKT 43 (YEL) to CKT 8 (GRY). |
| | The display brightness is then controlled by the panel and interior
lamps control switch. |
| • | The radio illumination bulb voltage is supplied by CKT 8
(GRY). |
Power Amplifier (Suburban Only)
| • | The optional amplifier boosts the sound of the 4 rear speakers
in the Suburban when equipped with the premium sound system. |
| • | With the ignition switch in the ACC or RUN position and the radio
control head ON, battery voltage is supplied to the power amplifier relay. |
| | Voltage is supplied through CKT 143 (PNK/BLK) and CKT 40
(ORN). |
| | The relay is grounded through CKT 150 (BLK) at IP ground 200. |
| • | When the relay contacts close, battery voltage is supplied to
the power amplifier through CKT 140 (ORN). |
| | The ground is completed through CKT 150 (BLK) at IP ground 200. |
Auxiliary Speaker-Z56
If the vehicle is equipped with option WX7 as part of the police package
Z56, the front door speakers are not connected to the radio. The speakers
are connected to a jumper harness blunt cut and coiled under the center
of the IP. The speaker connection allows the front door speakers to be connected
directly up to any aftermarket radio/communication equipment.
