I am rebuilding an 89 that was my fathers. The HVAC hasn't worked right since I got the car. I have been working on the dashboard and digital dash. I discovered the programmer is just dangling under the drivers side held up by the hush panel. I have the service manual and it appears that it should be mounted on the firewall. Am I going to have to remove the entire dash to get it in? Also, I didn't see any diagrams on how the vacuum lines are connected. there are at least 2 hoses off. 1 from the distribution connector on the outside and 1 from the black manifold inside the case. Any advice will be greatly appreciated as summer is coming quick here in Atlanta.

 

oh boy...

you've stumbled onto what I refer to as the "bastard box".

The 'programmer' has the unique ability to totally screw up a complicated elec a/c system by just being loose. It has to be mounted solid and pretty well level or the fragile and sensitive little servos cannot operate correctly. AND, its a B1t@h to get to...

one bolt, or nut (forget) thats about as awkward as it gets...but it CAN be done.
I take the seat out. lay towels on the studs to avoid more blood letting, then get in, upside down, face up head first feet in the cargo area and do whats gotta be done. It ain;t fun. You can try the prone position but you'll never be the same looking up at that angle....

it goes almost directly over the gas pedal...little to the rt. Look for the stud or reciever nut. I have a spare just to have something to curse when I have a bad day...so I'll find it and look for more detail on the vac lines and mount.

Its terribly awkward but IF you have a neighbor that likes beer and he happens to be a midget, thats helpful. Or a small child that listens will also work. Otherwise, make your chiro appt for monday and plan on mounting the 'programmer' on saturday. Do look at it for bad vac lines. There are a handful inside that are short and well bent. The rest is solid state circuit board. There are vac lines (1 or 2) that run to the dash to the far side. Inspect those for kinks or breaks.

Good luck !

I feel your pain.

 

sounds better than having to take the whole dash apart. Now I just have to find 2 hoses that don't have a home. Thanks

 

You're looking for thin hard plastic lines that do NOT look like vac lines. More like wire. Orange or yellow IIRC..

 

You should pull the diagnostic codes from the HVAC controller first. Here's a thread about how to do that:

http://forums.corvetteforum.com/c4-t...stic-mode.html

Then you can look into the HVAC programmer. I wrote some stuff on that too, with detailed pictures:

http://forums.corvetteforum.com/c4-t...schematic.html

 

Thanks for the tips. I was able to look up under the dash, right over the throttle and saw a square indention with a hole in it. I flipped the programmer over and kinda laid over the seat cushion and was able to get the unit back in place. I then found a small sheet metal screw and fastend it to the plenum. I started the engine and hit Auto. I actually felt air blowing from under the dash. I was confused at first cause I never felt it. I then lowered the temp to72 and the main vents started blowing. I hit the defroster and saw the lever move and air started coming out the defroster. Thank you for the advice. I should have posted here long ago instead of just searching.

 

Happy to have helped. Glad its fixed !

 

LOL, when my wife saw my contorted body position and legs hanging out the door, she just said "I am going in the house"!