Need help troubleshooting AC not working
Intermediate
Joined: May 2024
Posts: 25
Likes: 0
AC problem
Also, I checked the fuses, and for some reason they still won’t ground to the clutch to turn over when I click the AC button on my climate control somewhere in my car it is not grounding to the clutch.
Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,565
Likes: 4,034
From: Cape Coral, Florida
Most likely NOT a fuse (fuse 24) if your other mechanic jumped the relay and it works…again you likely have a control side issue so these mechanics will have to check a few things with a scan tool and or a DVOM…if they need help you can PM me their number and I will instruct them how to diagnose this…pretty easy !!…do you have the knowledge to do this yourself ??…some on here will write a novel on how to diagnose something and the OP doesn’t even own or know how to use a DVOM.
Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,565
Likes: 4,034
From: Cape Coral, Florida
Pro
Joined: Dec 2014
Posts: 682
Likes: 275
From: Cincinnati Ohio
My 2003 Chevy Corvette is having AC problems. I’ve replaced the fuse in the relays and my head unit is fine because I just bought a different one. I’ve changed the air temperature sensor. The clutch turns over cause I’ve gotten my other mechanic to wire something up to see if the compressor works and it’s turned over and it’s blown cold air, but for some reason the head unit when I click the button it starts to blink and no cold air will come out and it’s just straight hot air any solutions.
in my temperature on the exit temp keeps reading 69° when it’s 70-80+ degrees outside
in my temperature on the exit temp keeps reading 69° when it’s 70-80+ degrees outside
When is the last time you thought the a/c was cooling correctly?
Any discharge air temperature that is lower than ambient suggests your system is running so either your air temp measurement is incorrect or the system is running but may be cycling. I suggest you open the hood, turn on the a/c and see if the compressor is cycling on and off.
Do you have access to a/c gages and know how to use them?
Intermediate
Joined: May 2024
Posts: 25
Likes: 0
[QUOTE=Bill Curlee;1594820805]Well,,, unless you destroyed the Head Unit Electronics, I'm at a loss... 
Can you put your ear to the main center vent and while everything is QUIET, change the temp **** and see if you can hear the temperature door actuator motor spin?[/
I have a 2003 Chevy Corvette with AC problems. I’ve changed out the relays. I’ve checked to see if the compressor was fine. I’ve checked the air temperature sensors. I’ve checked the pressure sensors for the compressor and they’ve all checked out but still would not turn over after I clicked the AC button on my control unit just replaced that and it cannot be the control unit, so I tried pushing power to the relays to turn the compressor over and it turned over blowing cold air for a couple minutes and then going straight back to hot air and also manually went over to the passenger side fuse box and probe to put towards the compressor and still would not turn over any suggestions
Can you put your ear to the main center vent and while everything is QUIET, change the temp **** and see if you can hear the temperature door actuator motor spin?[/
I have a 2003 Chevy Corvette with AC problems. I’ve changed out the relays. I’ve checked to see if the compressor was fine. I’ve checked the air temperature sensors. I’ve checked the pressure sensors for the compressor and they’ve all checked out but still would not turn over after I clicked the AC button on my control unit just replaced that and it cannot be the control unit, so I tried pushing power to the relays to turn the compressor over and it turned over blowing cold air for a couple minutes and then going straight back to hot air and also manually went over to the passenger side fuse box and probe to put towards the compressor and still would not turn over any suggestions
Burning Brakes
Joined: Sep 2014
Posts: 775
Likes: 98
From: carroll ohio
pull fuse #27 in passenger foot well. wait about 20 min. then reinstall and put ign in acces. for about 10 minutes then start car. this could recalibrate the blend doors as it did on mine today. does not cost nothing and if it does not work you can go to the next troubleshoot plan.
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Racer
Joined: Aug 2023
Posts: 337
Likes: 74
From: New York
Correct if the clutch engages it could be a compressor issue. You need what is called a A/C manifold set (harbor freight $70, a set of Robinair couplers (part no. 18192) will make them easy to use. Just changed a compressor on a C5 Clutch engaged but Pressure in line did NOT. Compressor "no op". internally. no magic wand you need tools.
Pro
Joined: Dec 2014
Posts: 682
Likes: 275
From: Cincinnati Ohio
[QUOTE=Littleman55;1607867121]
To make any progress, you will need to put on a gage set as has been previously suggested and report back on the high and low side pressures.
Before doing that, I suggest you have an evacuation and recharge to ensure you have a system free of air contamination and at the correct charge level. Typically, enough charge goes into the system from the vacuum and then the compressor runs (without jumping the clutch) to pull in the rest of the charge. If your system will not do this, then you are back to an electrical issue but you will know the charge level is correct and you can safely run the system to verify the refrigerant side and the air handling sides are working properly by jumping your compressor clutch.
We have seen Forum members go through changing out sensors, such as the a/c high side pressure sensor, and C5Diag has walked them through problem solving to find out it was a connector or a wiring problem and not a bad sensor.
Well,,, unless you destroyed the Head Unit Electronics, I'm at a loss...
Can you put your ear to the main center vent and while everything is QUIET, change the temp **** and see if you can hear the temperature door actuator motor spin?[/
I have a 2003 Chevy Corvette with AC problems. I’ve changed out the relays. I’ve checked to see if the compressor was fine. I’ve checked the air temperature sensors. I’ve checked the pressure sensors for the compressor and they’ve all checked out but still would not turn over after I clicked the AC button on my control unit just replaced that and it cannot be the control unit, so I tried pushing power to the relays to turn the compressor over and it turned over blowing cold air for a couple minutes and then going straight back to hot air and also manually went over to the passenger side fuse box and probe to put towards the compressor and still would not turn over any suggestions
Can you put your ear to the main center vent and while everything is QUIET, change the temp **** and see if you can hear the temperature door actuator motor spin?[/
I have a 2003 Chevy Corvette with AC problems. I’ve changed out the relays. I’ve checked to see if the compressor was fine. I’ve checked the air temperature sensors. I’ve checked the pressure sensors for the compressor and they’ve all checked out but still would not turn over after I clicked the AC button on my control unit just replaced that and it cannot be the control unit, so I tried pushing power to the relays to turn the compressor over and it turned over blowing cold air for a couple minutes and then going straight back to hot air and also manually went over to the passenger side fuse box and probe to put towards the compressor and still would not turn over any suggestions
Before doing that, I suggest you have an evacuation and recharge to ensure you have a system free of air contamination and at the correct charge level. Typically, enough charge goes into the system from the vacuum and then the compressor runs (without jumping the clutch) to pull in the rest of the charge. If your system will not do this, then you are back to an electrical issue but you will know the charge level is correct and you can safely run the system to verify the refrigerant side and the air handling sides are working properly by jumping your compressor clutch.
We have seen Forum members go through changing out sensors, such as the a/c high side pressure sensor, and C5Diag has walked them through problem solving to find out it was a connector or a wiring problem and not a bad sensor.