GM vehicles w/Class II Data Bus system Uses factory speaker for chime Adjustable chime volume Generates a +12v switched output for aftermarket radios Automatic low voltage shutdown 3 switchable Retained Accessory Power RAP time modes (select vehicles) -Standard RAP -Extended RAP 20 minutes -Street RAP 60 minutes Illumination output wire -------------------------------------------------------------------------------- RED/BLACK WIRE = VSS SPEED PULSE SIGNAL (A/C VOLTAGE WHEN IN MOTION) RED/WHITE WIRE = REVERSE LIGHT TRIGGER (+12V WHEN IN REVERSE GEAR) YELLOW/BLACK WIRE = PARKING BREAK TRIGGER (-12V WHEN PARK BRAKE IS ON) ORANGE/WHITE = AUTO ILLUMINATION BLUE/WHITE = AMP TURN ON WORKS ON STANDARD RADIO (NON BOSE) AND STANDARD BOSE SYSTEMS WILL NOT WORK with OnStar, or PREMIUM BOSE systems (Y91) -------------------------------------------------------------------------------- TO EASILY DETERMINE DIFFERENCE BETWEEN STANDARD & PREMIUM BOSE SYSTEM -------------------------------------------------------------------------------- TURN FACTORY RADIO VOLUME UP AND DOWN RAPIDLY (IF THE SOUND REACTS IMMEDIATELY, THEN ITS A STANDARD BOSE) IF THERE IS A NOTICEABLE DELAY - THEN THE CAR HAS A PREMIUM BOSE / Y91 IF YOU HAVE A PREMIUM BOSE THERE IS A LINK AT TOP OF PAGE FOR THAT ITEM