Heater is blowing cold air. I have a chevy 2001 silverado extended cab, long wheel base. what could cause this?

SOURCE: 2004 Chevy Silverado Heater blows cool air

Check blend door actuator for operation

SOURCE: NO Heat in 1999 CHevy SIlverado

flush the heater out with a hose.   the fastest and cheapest.   if that dosen't work then replace the Air blend actuator motor.  $59.99 at Auto Zone  part    # 604-101

Jeffery Lewis

• 329 Answers
• Posted on Jun 03, 2009

SOURCE: 2004 Chevy Silverado AC is blowing warm air on passenger side.

You have dual zones that are controlled by temperature actuators the passenger side has lost its memory or has gone bad you can put it in self programming by disconnecting the battery for ten minutes then hook it back up start the truck turn the temperature control on but do not touch any other controls let it go thru the self programming for about 6 to 7 minutes then select your temperature you want if it still does not work properly you may have a bad actuator or a bad connection at the actuator

SOURCE: how do i change my upper and lower ball joints

Jack up the car remove wheel remove brake caliper and remove rotor rent a ball joint press remover and installer tool (at schucks you get money back when you bring it back) if it's 4 wheel drive you will have to remove the axle shaft next pull the snap ring off on the top side and put tool on the lower tie rod end and press out, next do the top press out top joint next sand ball joint sockets so it is clean lube with WD-40 next press in top ball joint and then lower ball joint. In this order otherwise you will have to un install the top ball joint by removing the pin then nut.

SOURCE: 1989 chevy silverado heater blowes cold air. both

Feel the hoses going into the heater on the firewall. If one is hot and the other is cool, then the heater control valve is not working for whatever reason. Check the flow valve.