Chevy Tahoe Front A/C Blows Warm- Clicking In Dash

Question:
A/C keeps blowing hot air with rapid acceleration rear a/c stays cool. 1998 Chevy Tahoe. Repairs made = new ac compressor , climate control, heater core valve, heater shut off valve.

Answer:
Hi Ruben, thanks for visiting. Could you give me a little more info please. On rapid accelerate, does it start to blow cold after you let off gas and stay steady? Do you hear any noises just before it starts to blow warm? Can you tell if the compressor cycles off when you hit the gas? This and any more info may be helpful for me to give some help, thanks.

VISITOR REPLY:
Thanks for responding. I dont have to floor it, example , jumping on the freeway, or passing a slower car. It might be a vacuum problem cause , i zipped tied the heater core valve closed and the problem went away but now no heater of course.

Answer:
Sounds like you are almost there. Check that the hose has vacuum and it switches when you turn the system from heat to cool. Check that the vacuum hose is routed correctly per the underhood vacuum diagram and let me know what you find.

Question:
2003 Chevy Tahoe 5.3L. When i turn on the a/c it makes a clicking noise and it only gets cold if you are driving and rear ac does not get cold at all as long as you are driving it is cold in front but if you stop ata light it does not stay cold and you can still hear the clicking sound thank-you.

Answer:
Todays AC systems can be very complicated. Some systems use several controllers, sensors, switches, relays and modules. Especially automatic, dual zone, and front/rear systems. To start with the basics, low freon charge is usually the reason for insufficient cooling. Normally low freon charge will give poor cooling under all driving conditions. You mentioned a clicking noise. If it is repetitive and coming from the dash area, a common problem is one of the blend/mode door actuator motors. Sometimes when they fail, they randomly search for a position.
There are also a few bulletins for ac problems.
1- The low pressure cycling switch in the receiver/dryer may malfunction. Sometimes a lite tap can help diag.
2- Adding an auxiliary fan in front of condenser.
3- May also be a control head reprogram update.
Would recommend having a dealer technician look at it. There may be trouble codes stored, and a technician will most likely have to look at several different data parameters to diag. Properly.

Question:
2003 Chevrolet Tahoe. When using my a/c , when i come to a stop. The blowing air turns from cold to warm. When i start running again it blows cold air.

Answer:
This first thing to do is haver the freon charged checked. If it is a little low, it will cause the compressor to kick off because the pressure got too low. Adding some freon will take care of that, but then you would have to look for a leak. Another possibility is that the throttle has a lot of carbon buildup. This will cause the idle to go too low, and the computer will kick off the compressor. Normally this would be accompanied by a rough idle or even stalling.

Question:
Where is the low pressure air conditioning valve located on my 2002 Tahoe. I see two valves on the high pressure side(small diameter line), but none on the low pressure (large diameter line).

Answer:
The two fittings that you see on the smaller line are what you're looking for. They are on either side of the orifice tube, so one valve is high pressure and the other is low pressure. You can hook up an A/C machine at that point, or if you're topping off the refrigerant with a can, attach it there as well. You will notice one valve is larger than the other, which is they way to tell high from low pressure. Make sure you check the sticker for the amount of R134A that the system takes.