2004 Pontiac Grand Am Stereo Wiring Harness - AutoZone Equip cars, trucks & SUVs with 2004 Pontiac Grand Am Stereo Wiring Harness from AutoZone. Get Yours Today! We have the best products at the right price. 2004 Pontiac Grand Am OE Wiring Harnesses & Stereo Pontiac Grand Am 2004, Factory Replacement Wiring Harness by Metra®, with OEM Radio Plug. For factory stereo. This high-quality Metra wiring harness is just what you need to replace your defective or aged factory wiring harness.