USAFPILOT

Regarding the same subject. On my 96 in "AUTO" the air blows out the vents but the heater doesn't seem to. Is there a reason for this. Does the cpu chose to heat the windshield and my feet. I can get hot air out the vents by selecting them but thats it.

Also, when the heater is on will it not recirculate the air in the cockpit, because when I chose that button in auto when the heater is on it quickly deselects it.

I guess I could read about this in the manual, but its out in the car and I dont feel like walking out ther opening the glove box etc. I'm

Midnite 88

That is normal operation on computer controlled heat/AC systems in most newer cars. There is a temp probe in the air mixer box that will close off the vents as to not have cold air blown on you when you want warm and vise versa.

rck1harley

I have a 96 coupe my air blows ice cold when I start it up and will stay cold until I shut the car off, when I start it back up and start driving its blowing hot if I leave the a/c on after driving awhile it start blowing cold again until I shut it off again. sometimes it will come on after a mile or so other times it will take 5 or 10 miles but it always come back on and blow ice cold . Any Ideas ?

Cliff Harris

The second picture in this post shows the problem. The fix is to cut about 1/8" off the ends of the nipples:

https://www.corvetteforum.com/1580705187-post33.html

It was only the '96 cars that had this problem. Earlier ones used hard nipples that did not collapse.

rck1harley

where are these locatated Cliff ?

sledge_78

I believe Cliff has one of the right fixes for this problem. The cause of the problrm is the "nipples" on the programmer box (under the dash) are made of a very soft plastic. When vacuum is present in the system these nipples collapse and resrtict the vacuum airflow from reaching the relays inside the box. When this happens the vent doors do not function or move into the correct position. As Cliff mentioned one fix is to cut off about 1/8" inch off the end of the nipple on the progammer box. These nipples are located where the multi tube connector plugs in. Another fix which works is to place a small piece of hard plastic tubing inside the nipple. Both fixes prevent the soft plastic nipple from collapsing when vacuum is present.
The fix is simple, but getting the programmer out from under the dash is the difficult part. So, before you venture out to replace the programmer box which may have the same problem, I would try and fix your existing one. These fixes do work.

Sledge_78

rck1harley

Thank you Sledge 78 , I think I will give it a Try I will let you know if it works. Thank s again.