Request a Pontiac Car Radio Stereo Wiring Diagram Whether your an expert Pontiac mobile electronics installer, Pontiac fanatic, or a novice Pontiac enthusiast with an Pontiac, a Pontiac car stereo wiring diagram can save yourself a lot of time. Automotive wiring in Pontiac vehicles are becoming increasing more difficult to identify due to the installation of more advanced factory oem electronics. Wiring Diagram - G8 Nation Looking for wiring diagram for 08 G8. Mostly need diagram for rear brake lights including third brake light. Friend is going to install device to make third brake light pulsate six times when brakes are applied. Need to find place to install it that will not require removing headliner, hopefully. Thanks 2009- Pontiac G8 Vehicle Wiring Chart and Diagram Listed below is the vehicle specific wiring diagram for your car alarm, remote starter or keyless entry installation into your 2009- Pontiac G8. This information outlines the wires location, color and polarity to help you identify the proper connection spots in the vehicle.