Defroster (front)

With the engine at full operating temp, locate the two heater hoses where they go into the firewall and feel them to see if they are both hot to the touch. If they are both hot, the heat in that vehicle is controlled by a blend door that regulates heated air flow. it is operated by a cable in this vehicle. The problem can be that the cable has broken or come off. This is what needs to be determined by examining the cable connection and see if it is responding to heat change commands or not.

This truck should also have a coolant control valve on the engine side that needs to have operation confirmed. Picture below.

Thank you, I will check both of these areas out.

Please let us know what you find. We are interested to see what it is.

Cheers, Ken