Problem with driver side A/C not cooling

Tiny
LOUIS W NAGY
  • MEMBER
  • 2002 CHEVROLET CORVETTE
  • 5.7L
  • V8
  • 2WD
  • MANUAL
  • 190,000 MILES
Driver side will not get as cold as it should.
The dash has been removed at this point, both blend doors work as they should, but the air temperature on driver side is about 10 degrees warmer than passenger side. Hard to trouble shoot without scanner. A diagram of what else is controlling the temperature would be helpful, or a flow chart of the system. Thanks
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Friday, November 15th, 2019 AT 5:23 AM

19 Replies

Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 42,554 POSTS
Hello,

This is common when the HVAC system needs to be re-calibrated. Here are the instructions on how to do so:

Re-Calibrating Actuators - HVAC System - Automatic
Vehicle Heating and Air Conditioning Testing and Inspection Programming and Relearning Re-Calibrating Actuators - HVAC System - Automatic
RE-CALIBRATING ACTUATORS - HVAC SYSTEM - AUTOMATIC
Use the following steps to perform the calibration update:
1. Turn OFF the ignition.
2. Remove the battery positive voltage circuit fuse of the HVAC Control Module.

IMPORTANT: The module memory will not clear if the battery positive voltage circuit fuse is installed in less than 60 seconds.

3. Wait 60 seconds.
4. Install the fuse.

Please let us know what happens.
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Saturday, November 16th, 2019 AT 1:12 PM
Tiny
LOUIS W NAGY
  • MEMBER
  • 55 POSTS
Really way past that, the actuators work as they should, the doors open and close as they should, The dash has been removed to facilitate operating the doors manually and the problem Has not changed, the driver side air is 10° warmer than the passenger side. What I need is a diagram, or a procedure that would help me find vacuum actuator that is not functioning properly.
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Saturday, November 16th, 2019 AT 7:26 PM
Tiny
LOUIS W NAGY
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  • 55 POSTS
The factory manual is designed to troubleshoot the system with a tech to dinner and the DMV as long.
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Saturday, November 16th, 2019 AT 7:27 PM
Tiny
LOUIS W NAGY
  • MEMBER
  • 55 POSTS
Sorry that last transmission was garbled. What I need is a better diagram or a flow chart or something that could lead me to the problem. The factory manual is no help it’s designed to use a tech two scanner which I do not have.
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Saturday, November 16th, 2019 AT 7:32 PM
Tiny
LOUIS W NAGY
  • MEMBER
  • 55 POSTS
I Assume that it is a vacuum actuator problem. I just need to know where it is located for the driver side.
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Saturday, November 16th, 2019 AT 7:35 PM
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 42,554 POSTS
When you remove the actuator can you move the air door pivot and hear the door inside the plenum closing completely? Here is more information about the left side blend door actuator and vacuum line diagrams.

Check out the diagrams (below). Please let us know what you find. We are interested to see what it is.
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Sunday, November 17th, 2019 AT 12:00 PM
Tiny
LOUIS W NAGY
  • MEMBER
  • 55 POSTS
Well, after a lot of trouble shooting I think I might have stumbled on to my problem, after poking around with my digital thermometer the evaporator acts like it has a restriction in it, I did this with the heater core blocked off, with the engine off and the engine on, same results.
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Saturday, November 23rd, 2019 AT 3:47 PM
Tiny
LOUIS W NAGY
  • MEMBER
  • 55 POSTS
So what do you thing, ever ran across this before , I did one time but it was on a old 1967 Chevrolet that the evaporator was half way freezing up but you could see it, this you can’t. Still not completely convinced this is problem. Going to check one more time. Any suggestions?
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Saturday, November 23rd, 2019 AT 4:00 PM
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 42,554 POSTS
Is the air conditioner fully charged? this guide will help you see what's going on:

https://www.2carpros.com/articles/re-charge-an-air-conditioner-system

High side should be about 260 psi at 65 degree. Please let me know.

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+1
Tuesday, November 26th, 2019 AT 11:24 AM
Tiny
LOUIS W NAGY
  • MEMBER
  • 55 POSTS
Just checked that ast week when this all started. For now I just evacuated and flushed Freon through high side and let it go out low side charged up with new dryer and it seems to be working for now. But really not sure how long it will last. Going to run it for a while and see. Thanks
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Tuesday, November 26th, 2019 AT 12:19 PM
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
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Nice work, we are here to help, please use 2CarPros anytime.
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Tuesday, November 26th, 2019 AT 1:02 PM
Tiny
C0RVETTE*
  • MEMBER
  • 1 POST
  • 2002 CHEVROLET CORVETTE
  • V8
  • 2WD
  • MANUAL
  • 34,000 MILES
I am a HVAC mech.,38yrs, but don't fool with auto AC anymore (enough relative and friends calling with electro/mechanical problems) Have a 02 Vette that has a small leak that I notice every 2yrs, probably cause it sits in the garage all winter. Want to know what is the proper head and suction pressure at a given outdoor temp (not in recirc. mode) and what discharge delta temp should I be at. I am aware of the critical charge the system operates at but don't want to go through a reclaim/pump down/recharge. If I'm going to do that I may as well tear it apart and fix the leak! Know the process for R12 but not sure about 134a even though I have a temp/pressure chart. Thanks in advance.


https://www.2carpros.com/forum/automotive_pictures/367757_GI2_1.jpg

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Tuesday, November 26th, 2019 AT 1:04 PM (Merged)
Tiny
MERLIN2021
  • MECHANIC
  • 17,250 POSTS
This what you need?
PERFORMANCE TESTS A/C PERFORMANCE TEST The following test measures the A/C system operating efficiency by comparing: à   The current ambient air temperature. à   The current relative humidity. à   The high side pressure of the A/C system. à   The low side pressure of the A/C system. à   The temperature of the air being discharged into the passenger compartment. 1. Park the vehicle inside or in the shade. Open the windows in order to ventilate the interior of the vehicle. If the A/C system was operating, allow the A/C system to equalize (about 2 minutes). Ensure that the ignition key is in the OFF position. Install the ACR 2000 Air Conditioning Service Center. Record the ambient air temperature displayed on the ACR 2000 Air Conditioning Service Center. Record readings of the low and high side static pressures. Are both the low and high side pressures within the specified value? à   Above 60 °F (16 °C) - 50 psi (345 kPa). à   Above 75 °F (24 °C) - 70 psi (483 kPa). à   Above 90 °F (33 °C) - 100 psi (690 kPa). If so, go to step 2 . If not, check for leaks. See LEAK TESTING in GENERAL SERVICING PROCEDURES article in GENERAL SERVICING. 2. Close the vehicle doors and windows. Open the driver door window 5-6 in (12.7-15.2 cm). Set the HVAC control to A/C in RECIRCULATION, Dual Zone system OFF, blower control to the highest position, HVAC control assembly to discharge air through the A/C outlets, temperature control to the coldest position and All A/C outlets open. Install temperature probes of the ACR 2000 Air Conditioning Service Center in the left and right center A/C air outlets. NOTE: Tools Required: ACR 2000 Air Conditioning Service Center (J-43600) or equivalent. NOTE: The ambient air temperature must be at least 60 °F (16 °C). Do not induce additional air flow across the front of the vehicle during the test. If you were sent here from a DTC diagnostic table, clear the DTC upon completion of this test. NOTE: When using the print function of the ACR 2000 Air Conditioning Service Center for this step it is necessary to press reset button before pressing the print button after the 5 minute operating time in order to capture the correct information. NOTE: Record the relative humidity and the ambient air temperature at the time of the test.
Apply the parking brake. Place transmission in Park (Automatic) or Neutral (Manual). Start the engine and allow to idle. Operate the A/C system for 5 minutes. Inspect for abnormal frost areas and unusual noises. Record the outlet air temperatures, the low-side pressure and the high-side pressure. Compare the low and high side pressures and the output temperatures to the table. See A/C PERFORMANCE SPECIFICATIONS table. Does all the data recorded fall within the specified ranges of the table? If so, go to 4 . If not, go to next step. 3. If the pressures and temperatures recorded do not fall within the specified ranges, continue to operate the A/C system for an additional 5 minutes. Record the pressures and temperatures again. Compare the low and high side pressures and the output temperature to the table. See A/C PERFORMANCE SPECIFICATIONS table. Does all the data recorded fall within the specified ranges of the table? If so, go to step 8 . If not, go to next step. 4. Do the high and low side pressures fall within the specified ranges but the outlet temperatures do not? If so, go to A/C PRESSURE ZONE "A" DIAGNOSIS . If not, go to next step. 5. Is the low side pressure higher than the specified range and the high side pressure within or lower than the specified range? If so, go to A/C PRESSURE ZONE "B" DIAGNOSIS . If not, go to next step. 6. Are the low and high side pressures both higher than the specified ranges? If so, go to A/C PRESSURE ZONE "C" DIAGNOSIS . If not, go to next step. 7. Is the low side pressure within or lower than the specified range and the high side pressure higher than the specified range? If so, go to A/C PRESSURE ZONE "D" DIAGNOSIS . If not, go to next step. 8. Operate the system in order to verify the test results. Did you find the same results? If so, system is okay. If not, go to SYMPTOM DIAGNOSIS under TROUBLE SHOOTING.


https://www.2carpros.com/forum/automotive_pictures/62217_vettea_1.jpg



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https://www.2carpros.com/forum/automotive_pictures/62217_vettec_1.gif

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Tuesday, November 26th, 2019 AT 1:04 PM (Merged)
Tiny
DOUG PETERS
  • MEMBER
  • 3 POSTS
  • 2001 CHEVROLET CORVETTE
  • V8
  • 2WD
  • AUTOMATIC
  • 98,000 MILES
Air conditioning working fine if sitting still, however once moving, does not keep up and air becomes warm.
Dealer wants to remove dash to get to ducts/doors.
Is this reasonable, or could it be vacuum problem?

I am also getting funny sound from under hood when compressor on. This is more recent then the warm air problem.
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Tuesday, November 26th, 2019 AT 1:05 PM (Merged)
Tiny
RACEFAN966
  • MECHANIC
  • 5,029 POSTS
Ok so let me ask a few questions to try to help. The cold to warm air problem sounds like it could be the blend door or blend door motor. Now the sound that you are hearing could be the a/c compressor or a/c clutch making noise. What you can do is get a long screwdriver and put one end of it on the a/c compressor and the other end cup in your hand and put you ear to it and listen to it, this will act like a stethescope. Let me know what you find with the noise and if you would like to fix the other problem yourself then let me know and we will do some testing to see if we figure out what it wrong. You may need a digital multi meter so let me know what you want to do. Thanks.
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Tuesday, November 26th, 2019 AT 1:05 PM (Merged)
Tiny
DOUG PETERS
  • MEMBER
  • 3 POSTS
Will check the noise, however this is more recent and when sitting still air is very cold.
What might be the fix with the blend doors/motor and how to get to it without major dash removal?
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Tuesday, November 26th, 2019 AT 1:05 PM (Merged)
Tiny
RACEFAN966
  • MECHANIC
  • 5,029 POSTS
Sorry a couple more questions so I can look over the wiring and vacuum diagrams for you car to better help you. This is a standard Vette or a Z06? Is your A/C manual or automatic? Get back to me with that so I look over the proper wiring a vacuum diagrams and we can get this fixed. I also must ask how is you mechanical skills? I just like to know so I do a better job of discribing what needs to be done. Thanks again.
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Tuesday, November 26th, 2019 AT 1:05 PM (Merged)
Tiny
DOUG PETERS
  • MEMBER
  • 3 POSTS
Corvette is standard, not Z06.
HVAC controls have auto and manual settings.
AC does not work properly in either.
I have sufficient mechanical skills for most repairs/understanding.

FYI, since I have had the car the passenger side vents have always allowed in outside air, but was never an issue until this year.
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Tuesday, November 26th, 2019 AT 1:05 PM (Merged)
Tiny
RACEFAN966
  • MECHANIC
  • 5,029 POSTS
OK lets see if the car can tell us anything with its self diagnostic system. Here is what you will need to do to see if the A/C system is holding any codes.
1. Turn on ignition. Press RESET button on DIC to see if any warning messages are pressent. Press and hold the OPTIONS button on DIC. While holding the OPTIONS button, press FUEL buttion 4 times in 10 seconds. System will enter automatic display mode followed by all DTC's (diagnostic trouble codes) present for all information systems. To enter manual display mode press any button except the E/M button as this will exit diagnostic mode.
2. Depress and button of DIC (driver information center) to enter HVAC mode of manual diagnostics. Make sure to write down all current and old DTC's. These DTC's will be a B followed by 4 numbers.
3. To clear codes - Turn on ignition and press the RESET button on the DIC and then press and hold OPTIONS and while holding OPTIONS press the FUEL button 4 times within 10 seconds as before then go to HVAC as before and press the RESET button in that mode and this will clear the codes.
Get back to me with any codes and I will look them up and see what it has to tell us. Thanks
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Tuesday, November 26th, 2019 AT 1:05 PM (Merged)

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