TDB87

Hey everyone, new to the forum. Looking for some help!
Ive got a 2003 suburban with front and rear dual auto climate control. The rear was cooling decent but front was not on either side. While going to check the charge the scrhrader got stuck on the high side and I lost the charge. I replaced the schraders and front orfice while at it and then pulled a vacuum and charged up with 48oz of r134 to match factory charge. Cycled on and it still wasn’t cooling to well. I checked and found the ac compressor belt was in semi rough shape with cracking. I replaced it. The tension pulley seems fine. I’ve got the truck up and running at 80degrees ambient the pressures were right around 50 on low side and 210 on high side and blowing 70 degrees out of the front vents. The ac coil is condensing like crazy. Looks like a swimmin pool under my truck when running.

There’s gotta be something going on under the dash I can’t find. So far I’ve checked and found:
The driver side blend door actuator. I’ve got it cycled in the closed position (lowest temp set point) and disconnected to make sure it stays closed. Also actually removed actuator and manually turned door open and closed. Closed it's the same luke warm air, open it's straight heat. Found the passenger and it's been disconnected in to cold position for a while. Apparently there is no cabin filter on this model and the evap coil is not easily accessible to check. There’s gotta be another blend door that lets in air from the heater core or something for me to be getting 70-74 at the vent when the cabin temp is roughly mid 70s and a 45-55 degrees evap coil. I thought about bypassing the heatercore just to take it out of the equation. But I know that’s not a fix.

Any help from anyone that’s tore apart a dash on a suburban or Tahoe from 2003 body style? I’ve YouTube and googled until I can’t anymore. All I find is these two actuators being common issues. Gotta be something else tho since I’ve got em disconnected and in closed positions.

I can also change the mode from floor, dash or defrost and it cycles fine but not cold on any mode for the front ac.

kevinkpk

If you take the heater core out of the equation, that would confirm what you think, something (blend door) isn't totally in correct position. Also isn't fixing, but confirming the problem. I'd revisit the blend door servo's, they don't have much travel, and I've had to replace one in my 03. If you're bypassing them open for a/c, you're still going to have to address that issue before winter, replacing them eliminates that issue, and possibly the a/c issue you're currently having.

Silverfox103

Watching this thread with interest, as I have been battling my 2001 Yukon XL with very similar issues for 6 months. I have replaced the actuator passenger side, swapped out the temperature control unit, passenger heater door seems OK. I did try clamping off the heater hoses, it took the heat out. Functions such as defrost, floor, bi level, seem to all function. Compressor seems to cycle on and off correctly. One thing I recently noticed AC tubes are not cold. Today it is in the shop with a trusted mechanic. I'm hoping he can figure it out. I will keep this thread updated, I'm guessing it will be the end of the week before I hear anything.

Tom

Silverfox103

Well the trusted mechanic did figure it out. It had two leaks, one of them you could hear (not with my hearing). Fixed those leaks, recharged and the AC works beautiful.

What I learned was everyone who says they service AC's can't. They may service it, but they can't fix it. The first two guys told me the actuators were weak, blend door broken and the controls were faulty. None of that was the case. I remember with the first guy somehow all the freon escaped when he was working on it. That should have raised the red flag.

Oh well it works now and I'm happy.

Tom