Dual Zone AC

[als99]

Just got a 99 with Dual Zone AC. Brought it to the local dealer who claims to be a Corvette specialist. It seems that the drivers side vent blows hot air regardless of the ac setting while the passenger side blows cool. If the mode is changed to blow from under the dash the the system starts to blow cool (but never cold). The dealer has now had it for a total of 10 days and claims that they can not find the problem. This car has 6000 miles and for all I know it may have never worked from the factory. Has anyone had or heard of this problem?

 

[danl72]

Have them check the vaccum lines and the A/C condenser. You should also see if there are any codes in the DIC. Good luck.

 

[c4c5specialist]

HI there,
Are there any codes in the HVAC??????
Please post them, c4c5

 

[John L]

Mine has started doing the same thing lately, only my particular situation is the reverse of yours. The passenger side blows luke warm while the driver side blows cool and responds correctly to commands. Mine set a DTC code on the DIC " 99 - HVAC 1 CODES B044 H C", which the service manual defines as: "Right Actuator Out of Range". So mine probably needs a new right side temperature control modulator. Some have reported success in getting the system back on line by disconnecting the battery for 20 - 30 minutes and then reconnecting it. Or pulling fuse # 27 from the passenger side footwell fuse box and then reinserting it, or both. Sometimes, this allows the system to reset by causing the actuators to move the temp doors through their full cycle and range of travel. You might try it. At any rate, you need to pull your codes. Good luck.

 

[crash1mac]

i heard their was a gm only bulletin concerning this. They need to something like re index the door on driver side maybe c4c5tech can shed some light on this subject i need fix for this problem also.

 

[c4c5specialist]

HI there,
JohnL is right on the money here.
Attempt the fuse removal first, and then let us know if the code resets.
Allthebest, c4c5

 

[crash1mac]

well got mine fixed today the pass side was still colder than driver after fuse pull.So off to a buddies shop for some other answers.We evacuated the system found out their was only 3/4 pounds of r134 in system.We vacuumed the system and put dye in the schrader(SP) valve was leaking ever so slightly.IT turned a almost 1/4 turn and sealed.We refilled the system with 1.60 pounds of r134 freon, Now its cccccoooooollllllldddd. Hope the schrader is where the leak was we will take another look in a week. All else fail take it to a shop to be sure you are looking in the right place.It turned out to be refrigerant related problem for me also.

 

[JR_Vette]

I would recommend pulling the battery and making sure it's not leaking, thus eating away the vacuum line that is directly below it. This is a pretty common problem with the non-AGM battery cars.