DRR

I have a '98 Vert with dual auto control hvac, and at the end of summer I started to get warmer air (+15 deg. ~) out of the driver side vents (even on recirc.) though the d/s temp control **** was set to full cold, and the pass. side vents blew nice and cold. Is this a control board issue? I'm hoping someone has repaired this problem already and can save me some time searching in my service manuals. Any advice?

Doug

stevezfl

Check for system codes. This happened on my 98 as well. Drivers side was blowing hot air and the passenger side was cold.

I had disconnected the battery the day before which apparently causes the codes, cause it's happened twice.

Run though the codes and you will probably find two HVAC codes that have to do with actuators being out of position.

Reset them and you will probably hear the actuator flaps moving under the dash. Hopefully back to where they belong.

Hope this works

DRR

Thanks Steve, I will have a look. So resetting the codes will resequence the actuators? I will let you know my results.

Thanks again,
Doug

MrPDJ

If no codes are present, then you likely have a low refrigerant charge. I used to have ice cold passenger side air and luke warm drivers side air. Turned out I had a very small leak. I fixed my leak and recharged and have not had the problem since.

If you try to fix this yourself (relatively easy to do with the right tools, many good posts on AC problems), put some UV dye into your system when you recharge it. Then run the system for a bit and use a black light to find your leak. Until you fix the leak (if this is your problem), you'll keep getting this issue. Most leaks can be fixed by replacing o-rings or seal washers. If you're lucky you can just tighten up on a fitting.

I would not advise that you use the refrigerant with stop leak additives. This causes more harm than good. Good Luck.