Possible AC problem
05-28-2016, 10:19 PM
#1
Possible AC problem
I've been doing some searching. I have a 98 Coupe. Disconnected the battery and whike doing the idle relearn, just in case, during the driving part I felt like the AC isn't cold like it used to be.
All functions seem to be working, but it's just not cold, I would consider it slightly colder than the vent. No codes, AC light stays on.
Is this possibly the well known Climate Control unit issue? Is it coincidence I noticed it after disconnecting the battery? Am I missing a simple fix/procedure I should do after disconnecting the battery?
All functions seem to be working, but it's just not cold, I would consider it slightly colder than the vent. No codes, AC light stays on.
Is this possibly the well known Climate Control unit issue? Is it coincidence I noticed it after disconnecting the battery? Am I missing a simple fix/procedure I should do after disconnecting the battery?
Last edited by Fayeilding; 05-28-2016 at 10:20 PM.
05-28-2016, 10:35 PM
#2
Le Mans Master
Probably low on freon...
05-28-2016, 10:52 PM
#3
Kinda hoping that's the case. But didn't know if it was possible it got out of calibration and needed an 01 unit that has "logic."
I've found a good bit of info about that problem, but not too much that describes the actual symptoms that would point to the climate control unit.
I've found a good bit of info about that problem, but not too much that describes the actual symptoms that would point to the climate control unit.
Last edited by Fayeilding; 05-28-2016 at 10:54 PM.
05-29-2016, 07:24 AM
#4
Racer
Sometimes your outside air temature sensor will go bad giving your a/c unit a false reading and shutting down the a/c function and just letting the vent air flow, this happened to me and I too thought that mine was just low on freon. I replaced the sensor ( cheap-around $9 at auto-zone ) and it fixed the problem perfectly for me. The outside sensor is located on the passenger side framerail under the headlight. Kinda tight to get to but you can do it with some finessing of your wrists and hands. Lift the Hood and go from the front of the car. Good luck, hope that's all it is with yours. CorvetteBob
05-30-2016, 03:30 PM
#5
Sometimes your outside air temature sensor will go bad giving your a/c unit a false reading and shutting down the a/c function and just letting the vent air flow, this happened to me and I too thought that mine was just low on freon. I replaced the sensor ( cheap-around $9 at auto-zone ) and it fixed the problem perfectly for me. The outside sensor is located on the passenger side framerail under the headlight. Kinda tight to get to but you can do it with some finessing of your wrists and hands. Lift the Hood and go from the front of the car. Good luck, hope that's all it is with yours. CorvetteBob
05-30-2016, 05:29 PM
#6
Sometimes your outside air temature sensor will go bad giving your a/c unit a false reading and shutting down the a/c function and just letting the vent air flow, this happened to me and I too thought that mine was just low on freon. I replaced the sensor ( cheap-around $9 at auto-zone ) and it fixed the problem perfectly for me. The outside sensor is located on the passenger side framerail under the headlight. Kinda tight to get to but you can do it with some finessing of your wrists and hands. Lift the Hood and go from the front of the car. Good luck, hope that's all it is with yours. CorvetteBob
Temp display seems correct. Was your display accurate when the sensor had gone bad? Just seems if it was bad it wouldn't display the right outside temp either.
Last edited by Fayeilding; 05-30-2016 at 05:29 PM.
05-31-2016, 04:06 PM
#8
Racer
Unfortunately these cars dont take freon. R12 was replaced by a newer refrigerant - r134. If the compressor is starting to get noisy, replace it along with the inline filter and dryer. Remember to add 2 ounces of refrigerant oil to the dryer in addition to replacing whatever amount of oil that came out of the system.
Last edited by don37; 05-31-2016 at 05:53 PM.
05-31-2016, 08:00 PM
#10
It's not noisy, everything seems perfect, just not as cold as it should be. Refrigerant is full and holding. Full meaning holding 50PSI on the low side with the ambient outside temp being 90 degrees. Which should be right on target based on ambient temp.
Last edited by Fayeilding; 05-31-2016 at 08:01 PM.
05-31-2016, 08:16 PM
#11
Racer
Have a look for any debris / leafs / trash on the front of the condensor.
Last edited by don37; 05-31-2016 at 08:17 PM.
05-31-2016, 09:09 PM
#12
He's not a Corvette specialist so to speak, but is extremely well versed and owned several, but hasn't owned a C5. Most of time a group owners like this will know more about its tendencies than mechanics unless they work a lot of them.
It only as 23k miles on it, but is a '98. No debris, no leaves, extremely clean, & extremely well maintained.
He charged it at night, in the garage it felt pretty cold, he was going to stick a thermometer in vent, but I had to go early.
In heat of day, not as cold.
Last edited by Fayeilding; 06-01-2016 at 12:33 AM.
06-01-2016, 12:32 AM
#14
Which brings up one of two questions.
Vegas has no humidity, Birmingham is extremely humid, is that the difference?
Or is the Vette unique to other cars in that regards?
I will say from sitting in the car while it was being charged there was a very noticeable difference going from 24 where we started to 35, then he came to check on it, it got colder still as he continued up to 50.
So it was definitely helping.
At night, it feels great. It's only during the real heat and humidity of the day it doesn't. It's still cooler, just feels like if I set my Lexus AC on 65 instead of low.
65 works great except in the middle of the day of an Alabama summer, then I have to go to low.
I know there's a reset procedure for the C5 HVAC, I assume it applies to a 98, may try that tomorrow.
Last edited by Fayeilding; 06-01-2016 at 12:34 AM.