My 2004 chevy Silverado 2500 hd 6.0 lt extended cab. passenger side vents blow hot when a/c is on and cold when heat is on

SOURCE: 2004 chevy subarban blows cold air on one side hot air on other side

i was a GM mechanic for many years, the problem you are having is one of your mode door actuators has gone bad, most of the time it is the actuator on the drivers side that causes the problems, i have seen this many times, sometimes you can take it to the dealer and they can hook the computer up to it and recalibrate it but most times it has to be replaced , it is located under the dash in the area above your gas pedal.

SOURCE: A/C and Heat Driver Side Intermittent Problem

You will need to replace your driver side temp actuator. It is most likely sticking or over travelling. It is located under the dash directly below the a/c control head. It is bolted to the a/c box upside down with two small bolts. Let me know if i can help more.

SOURCE: 2004 chevy silverado 1500 a/c heater

when my truck is at an idle, it won't put out any heat in the cab, same thing in the summer with the A/C, what's the fix for it ?

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

Harvey N Tawatao

• 3854 Answers
• Posted on Jun 22, 2009

SOURCE: 2004 Dodge Ram 2500 air conditioning

It sounds like your electronic vent actuator has gone bad, it's common to go bad and may need to be replaced. There are tinny gears that wear out and the vent actuator stops working. You can try this, turn the radio off first so you don't have to enter the reset code to activate your radio. Disconnect the battery for 30 seconds and reconnect it, if the actuator has lost it's base line and stuck in the open heat position, this will reset it, just make sure the setting is to cold and off before disconnecting and reconnecting the battery. If this does not work, then it's a bad actuator and Auto Zone should have the part you need and will have the step by step instructions for you to the job you self, I believe the dealer is a $415,00 repair cost for this. Good luck and keep me posted.