05 Yukon HVAC Control Operation

[DieselSlug]

All,

Back story:

I just splurged some coin to get my A/C back in operation on the Yukon. When I got it someone had several of the lines disconnected under the hood for reasons I don't know. I took it over to a buddy mechanic to try and get it working again. After replacement of 2 lines he had the system charged but the compressor was very noisy. Since we were this far in I had him replace the compressor too. In an effort to save some money we converted it to front A/C only (like a pickup) and plugged the rear A/C components. I may replace them and get them functioning next season if the front just isn't enough. So in short the A/C is now functioning in the front and blows great.

HVAC Operations Issue?:

I have the dual zone auto HVAC control with digital read out. My understanding to operate the A/C would be to hit the "snow flake" button, however currently when you hit the button the digital light flashes (I think with a line through it IIRC?) and then goes out. The A/C still functions though which is not like the findings on the interweb! Should it operate this way or not? I did see people replace an ambient sensor but this was if the system still didn't turn on. I will try to get a picture of it but may not be till Wednesday. Another strange thing is that every time I turn off the HVAC and then turn it back on it diverts to feet every time and I have to switch it back to chest. I don't recall it doing this with heat?

 

[MrMarty51]

All,

Back story:

I just splurged some coin to get my A/C back in operation on the Yukon. When I got it someone had several of the lines disconnected under the hood for reasons I don't know. I took it over to a buddy mechanic to try and get it working again. After replacement of 2 lines he had the system charged but the compressor was very noisy. Since we were this far in I had him replace the compressor too. In an effort to save some money we converted it to front A/C only (like a pickup) and plugged the rear A/C components. I may replace them and get them functioning next season if the front just isn't enough. So in short the A/C is now functioning in the front and blows great.

HVAC Operations Issue?:

I have the dual zone auto HVAC control with digital read out. My understanding to operate the A/C would be to hit the "snow flake" button, however currently when you hit the button the digital light flashes (I think with a line through it IIRC?) and then goes out. The A/C still functions though which is not like the findings on the interweb! Should it operate this way or not? I did see people replace an ambient sensor but this was if the system still didn't turn on. I will try to get a picture of it but may not be till Wednesday. Another strange thing is that every time I turn off the HVAC and then turn it back on it diverts to feet every time and I have to switch it back to chest. I don't recall it doing this with heat?

I think that the guy that put in the second post has all the answers but I just dont know how to translate it to tell You what the answer is.

 

[DieselSlug]

Haha, i haven't figured it out yet but at least the A/C works!

 

[BigDogYJ]

I wonder if the HVAC head unit was swapped with an aftermarket unit that was not for that truck, maybe wrong part #? Have you tried following the resync or relearn procedure for the HVAC controllers? If not I'll see if I can locate it.

 

[DieselSlug]

I wonder if the HVAC head unit was swapped with an aftermarket unit that was not for that truck, maybe wrong part #? Have you tried following the resync or relearn procedure for the HVAC controllers? If not I'll see if I can locate it.

Could very well have been swapped at one point in its life. I do have another unit in the basement that I pulled out of the JY last year to rob the non-"peeled" buttons out of for mine. I keep forgetting the processes that these trucks need for the relearn. I will have to try it.

I have noticed that if the temperature is "cooler" the A/C button (turning on the snowflake) does work, but the A/C does not feel as cold with it vs just cranking down the digits on the readout. Its almost like the A/C is always "on".

I plan to incorporate the rear A/C spring 2023 as on the hot days the front just wasn't enough for the rear (3rd row) passengers.