Where is the 1997 chevy PU heater control valve?
Some of the newer gm pickups are not equipped with coolant control valves-instead cooland constantly circulates through core- the only thing that regulates temp. is duct doors that divert the air away from the core. These duct doors are controlled by electric motors and can sometimes fail, or the ducts themselves will break or strip. If your model is equipped with a control valve it would be right at the firewall going into the cab, or right at the firewall on the cab side. Follow your heater core lines to firewall to locate.
