Hello I just bought a 2004 Tahoe lt. It has 75k and been sitting for a few months with a dead battery. The air only blows out on defrost. I tried disconnecting the new battery and it tried to cycle through the vents. It came out the vent for a couple seconds and then went back to defrost. Any ideas?
2004 hvac issues
- Thread starter Blibs
- Start date
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David Paul
Full Access Member
There is a way to reset the hvac. Try google. In the mean time I'll try and find the link. It has been posted here before.
David Paul
Full Access Member
I think this is it. I'd try the last rest procedure first.
Press the AC & Recirculation buttons simultaneously with your index & middle finger. (The recirculation button is right above the AC button). This causes the an instant temperature update to your system and allow your AC to come on and stay on afterwards. My Chevy service rep. looked up the problem on his GM computer while I stood there, then he printed this solution off for me.
The 3 blinks usually means something isn't in the correct position for the A/C to operate- either the mode control is in the wrong position (a/c doesn't work in defrost mode, etc.) or the compressor won't turn on for some reason. There is another reset procedure other than the one Nathanjax mentioned- first start it up and set all hvac controls to off, then shut off the engine, disconnect the positive battery cable, wait 10 minutes, then before reconnecting it touch it to the negative battery post for a complete discharge of the system. Reconnect the cable and start up the engine but don't touch the hvac controls for at least 5 minutes during which time all the actuators (mode, blend, recirc) recalibrate. After 5-10 minutes, try the a/c. This is the only thing that has worked for me in the past after I changed out parts of the system.
Press the AC & Recirculation buttons simultaneously with your index & middle finger. (The recirculation button is right above the AC button). This causes the an instant temperature update to your system and allow your AC to come on and stay on afterwards. My Chevy service rep. looked up the problem on his GM computer while I stood there, then he printed this solution off for me.
The 3 blinks usually means something isn't in the correct position for the A/C to operate- either the mode control is in the wrong position (a/c doesn't work in defrost mode, etc.) or the compressor won't turn on for some reason. There is another reset procedure other than the one Nathanjax mentioned- first start it up and set all hvac controls to off, then shut off the engine, disconnect the positive battery cable, wait 10 minutes, then before reconnecting it touch it to the negative battery post for a complete discharge of the system. Reconnect the cable and start up the engine but don't touch the hvac controls for at least 5 minutes during which time all the actuators (mode, blend, recirc) recalibrate. After 5-10 minutes, try the a/c. This is the only thing that has worked for me in the past after I changed out parts of the system.
