Power, Ground and Class 2
The instrument panel cluster (IPC) receives battery positive voltage from the left IP junction block IPC/HVAC BATT fuse, through CKT 1440 to terminal A4 (Pontiac) or A12 (Oldsmobile). The IPC receives ignition voltage (ACCY, ON and START) from the left IP junction block IPC/BFC ACC fuse, through CKT 1600 to terminal A8 (Pontiac) or A2 (Oldsmobile).
The IPC receives ground from CKT 151 to terminal A6 (Pontiac) or B7 (Oldsmobile)
The IPC receives all class 2 serial data messages on CKT 1807 at terminal A9 (Pontiac) or B1 (Oldsmobile).
Indicators
The IPC uses the class 2 serial data to light the various indicators and control the gauges. The SERVICE ENGINE SOON indicator is the only discrete input indicator circuit to the IPC. CKT 419 from the powertrain control module (PCM) to the IPC terminal B6 (Pontiac) or B8 (Oldsmobile) controls the SERVICE ENGINE SOON indicator.
The left turn indicator is controlled through CKT 14 to terminal A1 (Pontiac) or B10 (Oldsmobile) of the IPC. The right turn indicator is controlled through CKT 15 to terminal A2 (Pontiac) or B11 (Oldsmobile) of the IPC.
Instrument cluster illumination is controlled through circuit 8 from the lamp dimmer module to the cluster terminal A7 (Pontiac and Oldsmobile). The Oldsmobile cluster also uses a discrete switch input on circuit 376 to terminal B9 to control the trip reset odometer.
