C-4 HVAC Programmer
05-26-2012, 11:57 AM
#1
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Location: Gilmanton New Hampshire
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C-4 HVAC Programmer
I need to find an HVAC Programmer for a 1996 Cpe. with Electric Climate Climate Control. My HVAC controls have gone whacky!!
05-27-2012, 12:55 PM
#4
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No I'm not sure at all. My wife and I were in the car yesterday and the AC blew very cold indeed, but we were driving for an hour before it came out the dash vents. The only way I got it to work at all was to push the recirculate button, setting the climate control to 65. The air came out from the heater vent on the floor and the defroster vent on the dash. After about an hour it finally came out of the regular ac dash vents. I brought it to the dealer and they advised that I need the "programmer". GM does not manufacture the part any more, nor does any one else. Corvette Central would take them in and rebuild them for around $200, but according to their website they don't do that anymore. I found another place in Mass. that also rebuilds them, but they are closed for the long weekend. I'm going to have to wait till Tuesday to call them. I just don't know if they still rebuild them or not. without exchanging the part for a good one how would I know if it is the vacuum lines or the programmer????
VetteMed, Can you shed any light on the question about a proper diagnosis?? The tech at the dealership is pretty good, he has been there 30 years and works on 75% of the Vettes that come in, as well as all of the ones that I have had for over 25 years. I would assume he made a correct diagnosis, but who knows!!
VetteMed, Can you shed any light on the question about a proper diagnosis?? The tech at the dealership is pretty good, he has been there 30 years and works on 75% of the Vettes that come in, as well as all of the ones that I have had for over 25 years. I would assume he made a correct diagnosis, but who knows!!
05-27-2012, 03:01 PM
#5
Le Mans Master
No I'm not sure at all. My wife and I were in the car yesterday and the AC blew very cold indeed, but we were driving for an hour before it came out the dash vents. The only way I got it to work at all was to push the recirculate button, setting the climate control to 65. The air came out from the heater vent on the floor and the defroster vent on the dash. After about an hour it finally came out of the regular ac dash vents. I brought it to the dealer and they advised that I need the "programmer". GM does not manufacture the part any more, nor does any one else. Corvette Central would take them in and rebuild them for around $200, but according to their website they don't do that anymore. I found another place in Mass. that also rebuilds them, but they are closed for the long weekend. I'm going to have to wait till Tuesday to call them. I just don't know if they still rebuild them or not. without exchanging the part for a good one how would I know if it is the vacuum lines or the programmer????
VetteMed, Can you shed any light on the question about a proper diagnosis?? The tech at the dealership is pretty good, he has been there 30 years and works on 75% of the Vettes that come in, as well as all of the ones that I have had for over 25 years. I would assume he made a correct diagnosis, but who knows!!
VetteMed, Can you shed any light on the question about a proper diagnosis?? The tech at the dealership is pretty good, he has been there 30 years and works on 75% of the Vettes that come in, as well as all of the ones that I have had for over 25 years. I would assume he made a correct diagnosis, but who knows!!
05-27-2012, 04:05 PM
#6
Le Mans Master
If you search the C4 Tech forum for C68 (RPO for Automatic Climate Control) you will find a lot of info on typical failures and how to diagnose and fix them. I believe as mentioned above the most common failure is vacuum leaks. If you need a new control looks like you already have a good lead for one. 
05-27-2012, 05:51 PM
#7
Drifting
I have a 96 and it is the programmer on the firewall above the gas pedal that is causing the problem. If you do a search, you will find the threads dealing with the problem. The main problem is the 1996 programmer was a one year deal with soft nipples on the connector block coming out of the programmer itself. I just fixed mine but I did not take pictures. If you are willing to do some work and physical contortions, you can fix it for around $15.00. I took out my drivers seat, removed the hush panel and then the metal panel above it. You may also want to remove the sill cover and the speaker in the drivers side footwell for more room. Then get on your back with your legs in the hatch and your head under the dash. Look above the gas pedal and on the firewall is the programmer. The connector for the vacuum lines is attached with a press on nut in the middle of the colored lines. Some people pry it out but I used a long reach needle nose pliers and pulled the whole semi-clear rubber connector off pretty easily. Next remove on small bolt on the bottom and slide the programmer down. Then remove the locking tabs on the top connector and remove the top connector. To fix it some people trim the soft nipples and reattached with a locknut. I skipped it completely and removed the bolt and connector from the inside of the programmer. I got five feet of 7/64 vacuum line from NAPA and cut into five equal lengths, attached to the nipple in the programmer, drilled out the holes to a size that allowed me to slide the hose through the old connector. I also used 1/8 vacuum caps on the unused nipples in the programmer (may not be necessary). Then label the lines with painters tape for the right color vacuum line and insert a hard 1/8 vacuum connector into each vacuum line. Get back under the dash, plug the hard connectors into the corresponding color vacuum line on the semi-clear connector and reverse the rest of the installation.
Since then I have instantaneous changeover from floor to mix to vents to defroster whenever I press the button.
It is a pain but it is a permanent fix unlike replacement and will work for as long as the vacuum lines last.
Good luck either way.
Since then I have instantaneous changeover from floor to mix to vents to defroster whenever I press the button.
It is a pain but it is a permanent fix unlike replacement and will work for as long as the vacuum lines last.
Good luck either way.
05-27-2012, 05:59 PM
#8
Drifting
Oh and I forgot to add that if you decide to do it yourself, get some old blankets and/or a pillow to put on the driver seat metal frame that will still be on the floor after you remove the seat. And you should be able to find some pictures of the programmer if you do a search.
05-27-2012, 06:12 PM
#9
Le Mans Master
Oh and I forgot to add that if you decide to do it yourself, get some old blankets and/or a pillow to put on the driver seat metal frame that will still be on the floor after you remove the seat. And you should be able to find some pictures of the programmer if you do a search.