1990 GMC Sierra 2500
1990 GMC Sierra 2500 Stereo Wiring Information Radio Battery Constant 12V+ Wire: Orange Radio Accessory Switched 12V+ Wire: Yellow Radio Ground Wire: Black Radio Illumination Wire: Gray Radio Dimmer Wire: Brown Left Front Speaker Positive Wire (+): Tan Left Front Speaker Negative Wire (-): Gray Right Front Speaker Positive Wire (+): Light Green Right Front … Read more