01 Silverado Problems

[onebadbowtie]

Recently my heater/ac controls have been messing up. when i turn the temperature adjuster to cold it still blows hot air. I have tried every setting to see if i can get it to work and i got nothing. everything else works just fine though. Whats wrong with my controls? Do i need a new control unit?

Also the horn quit working recently so i checked the fuses and they are good. Next and i went to the salvage yard and got 2 working horns and put them on and they still dont work what should i check next?

Thanks James

[CrazyJesster]

i also had horn trouble with mine i repalced the horns relay and fuse. didnt seem to fix anything so i got an airhorn setup. never found a soulution i also have an 01. the controls im not too sure about i havnt had that problem yet.

[Gray Ghost]

Could be the heat/AC blend door malfunctioning....I've heard of that happening before.

[Jacfourteen]

I'd check to see if vacuum is getting to the control panel. I had a 97 cavalier that the vacuum line broke in the engine compartment and it had the same probs you mentioned.

[onebadbowtie]

I have found that if you select the temperature you want before you turn on the key then it works so what do you guys think now?

thanks for the responses

James

[MattA]

Horns short out frequently. Usually the lower one and often caused by water intrusion. If you replaced the horns you probably still have a bad fuse. Its in the underhood fuse block.

A/C problem is probably the temp door actuator. Its just to the right of the trans hump on the bottom of the a/c case. Often they will start clicking before they fail. The control head goes bad on them also so its a bit of a crap shoot without actually checking it out with a scan tool.

Try disconecting the battery for a few minutes. The actuators will resynchronize after loss of voltage. Sometimes this will bring them back.

[onebadbowtie]

ive checked the fuses and they are all good.

as for the heater i will try unhooking the battery and see if that does it. if not my brother has 99 gmc and im going to pull out his controller and try it in my truck and see if that fixes it. what kind of scan tool would i need to check this? and would the heater controls even through a code if it was messing up?

thanks James

[MattA]

You would need a Tech II or maybe an aftermarket type of scan tool. With a Tech II you can access the HVAC control module and test the actuators individually. Usually they will set an out of range code when they go bad. May have to go to a dealer for that. Possibly try an Autozone or something, sometimes they will check codes for you.

[onebadbowtie]

i finally got the problem solved. a horn wire grounded out and the fuse and the relay burned up. than me trying to fix things switched the ac relay with the horn relay and blew it to. So i fixed the wire and replaced the 2 relays and fuse and everything works like it should.

thanks for the help

James