Wont blow hot air - 2005 GMC Canyon

how old is the thermostat? are any hoses cracked or sucked together. heater core may need to be flushed or replaced? good luck!

Hello again. is your heater tap actually operating? its not stuck on hot is it? just check the tap actually moves when the hot cold selector is switched.

is it just the hot air that wont blow, or is it both hot and cold?

check heater control valve for rear heater, sounds like it's stuck shut

OK, a vacuum controlled blend door is the problem.

REMOVAL & INSTALLATION


See Figure 1

Fig. Fig. 1: Plenum door vacuum motors

1. Disconnect the vacuum hose at the motor.
2. Remove the 2 motor attaching screws.
3. Rotate the assembly so that the slot in the bracket is parallel to the tee-shaped end of the door crank arm, and pull the motor and bracket off the crank arm.
4. Installation is the reverse of removal.

--- Search for other vacuum motors under the dash to see if the vacuum hoses have somehow deteriorated or become detached. --- Try to look up your vehicle on autozone.com for other vacuum motors under the 'heater' section of the 'chassis electrical' section of the 'repair guide' after selecting your 1996 Ford f250 crew cab vehicle. http://www.autozone.com/autozone/repairinfo/repairguide/repairGuideContent.jsp?pageId=0996b43f8038ebd8

make sure it has a thermostat

is the heater tap working to let water through the heater core it may not be opening have to check operation of that

check thermostat and coolant level

hello,seem you need to send your car to authorized dealer to scan the problem,maybe the solution is only synchronizing all the flap,ty

you may need to change your thermastat