Pontiac Sunfire Stereo Wiring Harness - AutoZone Order Pontiac Sunfire Stereo Wiring Harness online today. Free Same Day Store Pickup. Check out free battery charging and engine diagnostic testing while you are in store. Pontiac Sunfire OE Wiring Harnesses & Stereo Adapters If you want to keep a number of different devices running safely, a superior wire harness is a sure-way to fit your individual needs. We have you covered with top-notch wiring harnesses designed precisely for your Pontiac Sunfire by the most trustworthy brands in the industry.