1500 Pickup

Improper HVAC Temperature and/or Air Delivery Due to Failed Mode Door Actuator on Chevrolet 1500 Pickup

Problem Description and Possible Solution

One or more heater & AC (HVAC) air delivery and/or temperature mode door actuator may fail. This can result in incorrect air delivery or temperature. If this occurs, fault code(s) stored in the HVAC control module should be available to assist with diagnoses.

Problem Data
RepairPal Verified
Average mileage: 174,160 (13,200–333,333)
10 model years affected: 1990, 1991, 1992, 1993, more1994, 1995, 1996, 1997, 1998, 1999
82 people reported this problem
Viewing 1 - 20 of 33 comments
I only get heat, even though the a/c is working properly. Fan is good. Someone has said the door is stuck in the heat position. Where is it located and the best way to fix it is how?
I have no heat only cold air coming through the vents changed thermostat still no heat. Heater core is flowing and heating up but still only cold air. I've seen people are talking about doors not opening to let air pass through the core. I can here them working opening and closing but not actually seeing the doors opening and closing could it be stuck? Please help
heater will not blow hot air and everything is working but hot air is non existant
heating door is not opening.Where is the door located
Heater blows cold air instead of heat. Need to know where all hvac temperature mode door actuator locations are
Heat only blows out cold air I believe blend door actuator is bad. Where is it located on 1998 Chevy Silverado
When blower motor is on 2 highest settings,air can be heard roaring in the vent system but the proper amount of air volume coming from vents is not as when newer.Took door actuator off and seems to be working fine off of unit. Will explore the possibility of mode actuator being stuck or bad.The search for this problem continues.Post 5/26/2011.
only blowing luke warm air on high heat not fixed yet
No heat! replaced blend door actuator
air will not completely quit blowing from defrost vent
my truck is putting out hot air with everything off. no blower on just being able to feel heat while driving
When moving selector knob from its current position to any other position, mode door makes a clicking sound as it attempts to move. Haven't replaced it yet as I still need to check if the door is stuck. Even after freeing a stuck, still a good idea to replace motor.
Sometimes when driving down the road and I let down my window and then AC quits blowing out cold air; however, very hot air begins blowing out from underneath the steering wheel. When I let up the window the AC just blows out warm air out the vent and the hot air quits blowing out from under the steering wheel. It takes a days and/or months to blow out cold air again. I have not found a fix for this yet. I have just started reseacrhing the problem.
bought truck all worked , then at 200-k the defroster wont blow air at winsheild , center and floor works no blower problems , just the defroster
going to look at back of control knob , board of some kind
Took off old actuator and it did not any power so i filped the door around and the heat worked, so I tryed to find a actuator at parts house but never got the right one, i am still looking for the right one .
hi speed relay don work were is it locate the actuator make a taping sound and run afert engine is off and it stop after 10 second,

replace actuator
Actuator only moves about half way, heats get less but still hot.
A.c. doesn't blow completely cold also doesn't have the velocity it used to have. Replaced compressor, hoses and condenser with no change.