Climate control issue

[clifford_H3T]

'09 Hummer H3T Adventure 5cyl 109k

Hey guys, I have something going on with my climate control, the a/c only blows cold on the far left setting but goes to hot one notch over. I've already done the climate unit reset (hold a/c, defrost till blinking stops) but that didn't seem to help the problem. Do I have to buy a whole new unit? Thanks for the help guys.

 

[alrock]

Here is the fix from our friend Hunner. This is an OLD problem that I haven't seen come up in years. Heck, it's so old you could still find Radio Shack stores.

The procedure here is the HUNNER method of installing it. Proceed at your own risk.

• I did not disconnect the battery as I wanted to confirm this resistor fixed it instead of by some fluke disconnecting the battery did.
• Set the parking brake. Turn the key on.
• It helps to shift to Low. However leaving the key on will drive you nuts so after removing the dash piece I put it back in park.
• Disconnecting the battery would of course shut the dinger bell off. So I would recommend that and you can leave it in low to have more room, now that we know this did fix it. (fingers crossed)
• First you have to do the stick your fingers in the DC sockets and pull up and out.
• I cut me a piece of cardboard for a work surface in case solder dropped.
• I disconnected the plug from the back of the switch to get more room to work
• Find the light blue wire with black stripe. I peeled back the high quality gooey sticky black electrical tape GM chose to use far enough to expose the wire back into the loom so I could slide on some shrink wrap long enough to cover the splice.
• Call me old school, I'm old and went to school, but just as in my battery thread I make a physical connection first then solder.
• I used some forceps for a heat sink.
• Solder in that wire a Radio Shack 68 ohm 1/2 watt resistor. They come 5 to a pack for $1.30 or $.26 a piece.
• If you don't know, use a low wattage iron so as not to fry the insulation on each end. Heat the wire until it pulls some solder as you feed it.
• Use some fine solder, Radio Shack still has that!
• Grabbed a short piece of shrink wrap I keep around. After the solder area cools slide the shrink wrap you remembered to slide on BEFORE you soldered over the entire splice. Use a heat gun carefully to shrink the wrap and secure and insulate your splice. I did not re-tape it at this time as I wanted to test it first. I will use a high grade of black electrical tape or some loom.