GM's 2004 Chevrolet Pickups were available with heaters, heater and air conditioning combinations and a dual automatic climate control system that allows for separate settings for passenger and driver. Problems with the systems can be related to the temperature being incorrect, the air flow not being adequate, and environmental issues like misting and odors. Problems like these can be rectified through troubleshooting.
Clear snow, ice and leaves from the air inlets at the base of the Chevy pickup's windshield if the HVAC system isn't working right. This vent is the master input vent and is very important because it provides the air throughput for heating, cooling and ventilating.
Remove shopping, toys and other items from underneath of the front seats in extended cab pickups that use rear seating. Air is distributed to the rear through vents under the front seats.
Uncover the sensors if temperature isn't being maintained on the automatic system. Sensors are found in the headliner, and there's also one in the defrost grille in the middle of the instrument panel that monitors solar heat.
Turn the air conditioning part of the HVAC to "Recirculation" if outside odors are entering the pickup. "Recirculation" can't be used with "Floor," "Defrost," or "defog" modes, however. The indicator light flashes three times if you try.
Try removing any hood deflectors if you continue to have problems. GM says that its hood deflector won't cause HVAC problems, but that other makers' devices could affect air distribution.
