OER Parts offers a wide selection of Air Conditioning and Heater Parts for your 1985 GMC C2500 Suburban. OER Parts offers 1985 GMC C2500 Suburban Air Conditioning and Heater Control Panels, 1985 GMC C2500 Suburban Air Conditioning and Heater Knobs, 1985 GMC C2500 Suburban Air Conditioning and Heater Levers and Cables, 1985 GMC C2500 Suburban Air Conditioning and Heater Relays, 1985 GMC C2500 Suburban Air Conditioning and Heater Switches.