Ac Blows Heated Air

[elvispresley]

1999 gmc z 71. out of the blue my ac starts blowing heated air. on agian then off agian until now it is blowing heated air every time i turn the ac on. it stays blowing this hot air no matter where i set the dail blue to red. i do believe i heard the door flap shut the last time it switched.

can someone please point me in the right direction. if its an actuator, how would i determine which one and where. is there a schematic, or diagram that i could download.

any help is greatly appreciated.

[bill190]

This is usually an actuator problem. There are little electric motors which open/close doors which switch from hot to cold.

 

But knowing the exact location of the door in question, how your specific system should operate, how to troubleshoot the problem, and procedures for replacing the actuator (if that is the problem), requires the GM Factory Service Manual set for your year/model vehicle. You can order that from helminc.com or a GM dealer.

 

You would also need to know how to use a multimeter for troubleshooting.

 

How to use a multimeter...

http://www.google.com/search?hl=en&saf...ter&aqi=g10

[elvispresley]

This is usually an actuator problem. There are little electric motors which open/close doors which switch from hot to cold.

 

But knowing the exact location of the door in question, how your specific system should operate, how to troubleshoot the problem, and procedures for replacing the actuator (if that is the problem), requires the GM Factory Service Manual set for your year/model vehicle. You can order that from helminc.com or a GM dealer.

 

You would also need to know how to use a multimeter for troubleshooting.

 

How to use a multimeter...

http://www.google.com/search?hl=en&saf...ter&aqi=g10

 

thanks for the quick response. roughly, how much would that be? and how long would it take? {best case to worst case scenario} average mechanical skills.

my local jiffy lube mechanic looks under glove box, and says the dash has to come out. 5 hours labor he says plus the price of the parts. then he looks something up on the computer, goes back and looks under the steering wheel and says if he can do it in a shorter amount of time he would try to save me some money, but said to be expect 500 to 600 dollars.

i really cant afford that right now and am trying to save some money. so any hints, tips, or info is really appreciated. thanks guys

[txab]

Here are a few links:

 

http://www.gm-trucks.com/forums/index.php?...c=99963&hl=

 

http://www.gm-trucks.com/forums/index.php?showtopic=98574

 

http://www.gm-trucks.com/forums/index.php?showtopic=67578