A/C system help - '93
Thread Starter
Drifting
Joined: May 2007
Posts: 1,426
Likes: 165
From: Motor City
A/C system help - '93
Currently, the a/c system in my 93 is not working. The car has the C68 option. a/c has not worked in years, and in the past I have noticed the button lights flashing, however they are not anymore.
After some research I've done the diagnostic procedure on the control unit and found no codes (showed 00). Not lights are flashing on the buttons at this time.
Next, I went to the compressor cycling switch and jumped the connection. Compressor fired up, however I didnt let it run enough to see if it was blowing cold air (didnt want to damage anything).
So does this mean the compressor cycling switch is the culprit? If so, can someone direct me to the correct part to purchase.
Thanks.
After some research I've done the diagnostic procedure on the control unit and found no codes (showed 00). Not lights are flashing on the buttons at this time.
Next, I went to the compressor cycling switch and jumped the connection. Compressor fired up, however I didnt let it run enough to see if it was blowing cold air (didnt want to damage anything).
So does this mean the compressor cycling switch is the culprit? If so, can someone direct me to the correct part to purchase.
Thanks.
Pro
Joined: Jan 2004
Posts: 676
Likes: 196
From: Chester SC
St. Jude Donor '15-'16, '21,'24
This worked for me
Dubin, sorry I cannot give you instructions right now, but a simple fix might be to remove the AC/heater touch pad cluster and clean the contacts with a pencil eraser.
If I can do it, anyone can! ... hope this helps.
HKW
If I can do it, anyone can! ... hope this helps.
HKW
Thread Starter
Drifting
Joined: May 2007
Posts: 1,426
Likes: 165
From: Motor City
Ok will do..I thought I read somewhere on here that jumping the compressor cycling switch is an indication of a faulty one or low gas. However I don't get the low gas code even after a battery reset...Ill reset it again when I get home Sunday and post up the results.
Pro
Joined: Aug 2009
Posts: 725
Likes: 4
From: Plano, TX
The C68 on the 93 is a PIA to diagnose. There are many many things that can cause the compressor to not come on. You will need a wiring diagram and Factory Service Manual.
1. Start with the easiest which is low freon. (should be about 70psi static)
2. Then check AC programmer and AC clutch fuses.
3. Try grounding the lt blue wire that goes into the AC programmer(bad ac programmer)
4. You can eliminate certain things by getting the compressor to turn on further and further up the wiring diagram.
etc etc
Hope this helps.
1. Start with the easiest which is low freon. (should be about 70psi static)
2. Then check AC programmer and AC clutch fuses.
3. Try grounding the lt blue wire that goes into the AC programmer(bad ac programmer)
4. You can eliminate certain things by getting the compressor to turn on further and further up the wiring diagram.
etc etc
Hope this helps.
Currently, the a/c system in my 93 is not working. The car has the C68 option. a/c has not worked in years, and in the past I have noticed the button lights flashing, however they are not anymore.
After some research I've done the diagnostic procedure on the control unit and found no codes (showed 00). Not lights are flashing on the buttons at this time.
Next, I went to the compressor cycling switch and jumped the connection. Compressor fired up, however I didnt let it run enough to see if it was blowing cold air (didnt want to damage anything).
So does this mean the compressor cycling switch is the culprit? If so, can someone direct me to the correct part to purchase.
Thanks.
After some research I've done the diagnostic procedure on the control unit and found no codes (showed 00). Not lights are flashing on the buttons at this time.
Next, I went to the compressor cycling switch and jumped the connection. Compressor fired up, however I didnt let it run enough to see if it was blowing cold air (didnt want to damage anything).
So does this mean the compressor cycling switch is the culprit? If so, can someone direct me to the correct part to purchase.
Thanks.
Thread Starter
Drifting
Joined: May 2007
Posts: 1,426
Likes: 165
From: Motor City
^^Thank for the pointers.
I pulled the battery cable for a few minutes and connected it. Still no flashing lights or codes stored. I'll have to take it up to the shop to get pressures checked in the system. Somehow, I feel this is going to be an expensive fix, but hopefully not!
I pulled the battery cable for a few minutes and connected it. Still no flashing lights or codes stored. I'll have to take it up to the shop to get pressures checked in the system. Somehow, I feel this is going to be an expensive fix, but hopefully not!
Le Mans Master
Joined: Dec 2000
Posts: 7,839
Likes: 22
From: San Diego, Ca
Without Codes, it's usually a bad connection at the Low Pressure Switch. Use your DVM to see if the switch contacts are closed. They should be, even if it's only half full. If it reads open, it's probably out of gas, but if it's closed, try wriggling around the harness or just holding it onto the switch.
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Thread Starter
Drifting
Joined: May 2007
Posts: 1,426
Likes: 165
From: Motor City
Without Codes, it's usually a bad connection at the Low Pressure Switch. Use your DVM to see if the switch contacts are closed. They should be, even if it's only half full. If it reads open, it's probably out of gas, but if it's closed, try wriggling around the harness or just holding it onto the switch.
Thread Starter
Drifting
Joined: May 2007
Posts: 1,426
Likes: 165
From: Motor City
SunCr could you help me measure the low pressure switch contacts...I assumed the sensor was 2 pin like the cycling switch but it is a three pin switch. Do you happen to know which pin/wire is what?
Thread Starter
Drifting
Joined: May 2007
Posts: 1,426
Likes: 165
From: Motor City
Okay, some more help is necessary. I'm confused as to which sensor is which. Based on the FSM there is a pressure cycling switch and a a/c refrigerant pressure switch but I cant figure out which one is which.
I've pasted pictures below.
**Both switches
**Top switch (big tube, 2 pin)
**Bottom switch (small tube, 3 pin)
The top switch looks like this from CC: This is a AIR CONDITIONING COMPRESSOR ENGINE COOLANT TEMPERATURE SWITCH according to them, not a pressure cycling switch like the FSM says.
http://www.parts123.com/parts123/yb....Z5Z5Z50000050F
Help me out here...
I've pasted pictures below.
**Both switches
**Top switch (big tube, 2 pin)
**Bottom switch (small tube, 3 pin)
The top switch looks like this from CC: This is a AIR CONDITIONING COMPRESSOR ENGINE COOLANT TEMPERATURE SWITCH according to them, not a pressure cycling switch like the FSM says.
http://www.parts123.com/parts123/yb....Z5Z5Z50000050F
Help me out here...
Last edited by 9T3VETTE; Jul 7, 2012 at 07:33 PM.
Thread Starter
Drifting
Joined: May 2007
Posts: 1,426
Likes: 165
From: Motor City
thanks for the response...could you direct me to the correct part?
Looking online, the "cycling switch" on mine looks nothing like any of the cycling switches I can find. A search only reveals the following...
http://www.ecklerscorvette.com/catal...&x=0&y=0&cat=3
or (this looks like my "cycling switch" but doesnt state that it is)
http://www.parts123.com/parts123/yb....Z5Z5Z50000050F
Looking online, the "cycling switch" on mine looks nothing like any of the cycling switches I can find. A search only reveals the following...
http://www.ecklerscorvette.com/catal...&x=0&y=0&cat=3
or (this looks like my "cycling switch" but doesnt state that it is)
http://www.parts123.com/parts123/yb....Z5Z5Z50000050F
Safety Car
Joined: Jun 2006
Posts: 3,629
Likes: 28
From: FL
thanks for the response...could you direct me to the correct part?
Looking online, the "cycling switch" on mine looks nothing like any of the cycling switches I can find. A search only reveals the following...
http://www.ecklerscorvette.com/catal...&x=0&y=0&cat=3
or (this looks like my "cycling switch" but doesnt state that it is)
http://www.parts123.com/parts123/yb....Z5Z5Z50000050F
Looking online, the "cycling switch" on mine looks nothing like any of the cycling switches I can find. A search only reveals the following...
http://www.ecklerscorvette.com/catal...&x=0&y=0&cat=3
or (this looks like my "cycling switch" but doesnt state that it is)
http://www.parts123.com/parts123/yb....Z5Z5Z50000050F
I used one of these recently on a 93 and it worked well. Ask for a new o-ring when you order, it does not come with the new switch and I had a leak until I could replace it, I do not know the part number because I used one of a universal kit, sorry.
Thread Starter
Drifting
Joined: May 2007
Posts: 1,426
Likes: 165
From: Motor City
Yeah it looks like the correct sensor....
http://www.ebay.com/sch/i.html?_trks...-2628&_sacat=0
Wonder why the corvette part websites dont have this one?? Maybe someone else has had this trouble too??
http://www.ebay.com/sch/i.html?_trks...-2628&_sacat=0
Wonder why the corvette part websites dont have this one?? Maybe someone else has had this trouble too??
Le Mans Master
Joined: Dec 2000
Posts: 7,839
Likes: 22
From: San Diego, Ca
Available at any Discounter - shape shouldn't matter as longer as the harness matches up. O'Reilly sells a kit which includes a new
Connector which may be what it needs. If you have a Scanner, though, I'd check the Pressure Sensor voltage/signal (that's the 3 wire Sensor on the High Pressure - smaller - line). If it's 0 or a great deal less than the static pressure for ambient (for example, if it's 75 degrees it should be about 78 psi) it's out of gas and that may not set the Low Pressure Code - especially if it oozed out while it was sitting.
Connector which may be what it needs. If you have a Scanner, though, I'd check the Pressure Sensor voltage/signal (that's the 3 wire Sensor on the High Pressure - smaller - line). If it's 0 or a great deal less than the static pressure for ambient (for example, if it's 75 degrees it should be about 78 psi) it's out of gas and that may not set the Low Pressure Code - especially if it oozed out while it was sitting.
Thread Starter
Drifting
Joined: May 2007
Posts: 1,426
Likes: 165
From: Motor City
^^Hmm interesting..thanks for all the help guys. I dont have the pressure measuring equipment, so i'll be taking it into a shop to have the pressure checked out and the system looked at. I'll let you know what comes out of the visit.
Intermediate
Joined: Aug 2008
Posts: 48
Likes: 1
From: Glendale AZ
dublin4life, I am having the same issue with my '92. Did you install the part suggested by toptechx6? I was going to order one, but when I did the ordering system says it's not for my car. Its for a Buick, if I remember correctly.
I bought 2 that were suppose to be for my car and didn't work. The inside diameter wasn't right and they wouldn't stay on. One wasn't even the right thread. But that's what I get for going with a autozone part. Too anxious to get it fixed, I guess. I live in AZ it is really hot here.
I bought 2 that were suppose to be for my car and didn't work. The inside diameter wasn't right and they wouldn't stay on. One wasn't even the right thread. But that's what I get for going with a autozone part. Too anxious to get it fixed, I guess. I live in AZ it is really hot here.
Thread Starter
Drifting
Joined: May 2007
Posts: 1,426
Likes: 165
From: Motor City
As a follow up, I took the 93 to a trusted mechanic in my area that has the capability/license to work on R12 systems.
Come to find out the car had been converted at some point in it's life to R134a, which I did not know.
They put a vacuum on the system for 30 minutes, which held no problem. Checked all the main components and filled the system with 134a, oil and dye and ran for 30 minutes at max setting. No problems, compressor kicked on and blew cold with no visible signs of a leak.
Looks like the system was just empty of gas. Now I have a/c for the first time in a long time!!
Thanks for all the help guys.
Come to find out the car had been converted at some point in it's life to R134a, which I did not know.
They put a vacuum on the system for 30 minutes, which held no problem. Checked all the main components and filled the system with 134a, oil and dye and ran for 30 minutes at max setting. No problems, compressor kicked on and blew cold with no visible signs of a leak.
Looks like the system was just empty of gas. Now I have a/c for the first time in a long time!!
Thanks for all the help guys.