GMC Vandura G2500 (1985-1995) Instrument illumination circuit

AUDIO ALARM MODULE (BELOW I/P FUSE BLOCK) LIGHTS ON INPUT BLK WIRE BRN WIRE DK GRN WIRE FUSE BLOCK- I/P FUSE BLOCK: I/P INSTR LPS FUSE GRY WIRE HEADLIGHT SWITCH HEATER, A/C CONTROL ILLUM. LAMP HIGH DIM HOT AT ALL TIMES I/P DIMMER SWITCH INSTRUMENT CLUSTER LIGHT SWITCH OFF HEAD PARK ORG/ WIRE PRNDL ILLUM. LAMP RADIO SOLID STATE TAIL LPS FUSE