1999 C5 A/C Issue
Thread Starter
Cruising
Joined: May 2014
Posts: 10
Likes: 0
From: Kent WA
1999 C5 A/C Issue
Sorry - new to Corvettes and this forum. You've probably be inundated with this question, but I haven't found the answer. The A/C blows cold and hot as directed, but it will not change locations. No matter what I input on the control head it just blows out of every outlet. It is the dual zone automatic unit and the control head is new. I'm not mechanical so I will need to take it to a local shop or a dealer. I just want to know what I am looking at for repairs. Thanks!
Burning Brakes
Joined: Jun 2010
Posts: 1,014
Likes: 5
From: Rockwall TX
There is a small vacuum line from the back of the manifold that can break, or the line continues under the battery and it has a tendency to break due to battery acid. You could probably check both yourself.
Intermediate
Joined: Oct 2011
Posts: 25
Likes: 0
Driver Side Hot Air
Yup, I've got the problem. Had most of the A/C unit redone by dealer last September, all the way down to the firewall, and had the assembly motors and just about everything else replaced.
A/C worked OK until about a month ago. I checked and have no DIC codes for HVAC.
Couple of questions about some of the procedures that I've read about in here:
1. I've pulled and reinstalled breaker #27 at least 15 times, to no avail. I have seen some threads that say turn the key off, and some say leave it on. Does anyone any more specifics. I've tried with key in OFF, key in ON, with engine off, and with engine running.
2. If I try pulling the negative battery terminal, do I do that with the engine running, and/or what key position.
A/C worked OK until about a month ago. I checked and have no DIC codes for HVAC.
Couple of questions about some of the procedures that I've read about in here:
1. I've pulled and reinstalled breaker #27 at least 15 times, to no avail. I have seen some threads that say turn the key off, and some say leave it on. Does anyone any more specifics. I've tried with key in OFF, key in ON, with engine off, and with engine running.
2. If I try pulling the negative battery terminal, do I do that with the engine running, and/or what key position.
Le Mans Master
Joined: Mar 2011
Posts: 6,835
Likes: 302
From: Columbia SC
Sorry - new to Corvettes and this forum. You've probably be inundated with this question, but I haven't found the answer. The A/C blows cold and hot as directed, but it will not change locations. No matter what I input on the control head it just blows out of every outlet. It is the dual zone automatic unit and the control head is new. I'm not mechanical so I will need to take it to a local shop or a dealer. I just want to know what I am looking at for repairs. Thanks!
http://forums.corvetteforum.com/c5-t...diagnosis.html
Le Mans Master
Joined: Mar 2011
Posts: 6,835
Likes: 302
From: Columbia SC
Re-Calibrating Actuators
Use the following steps to perform the calibration update:
1. Turn OFF the ignition.
2. Remove the fuse for the HVAC Control Module (fuse #27 in the I/P fuse box).
Important
The module memory will not clear if the battery positive voltage circuit fuse is installed in less than 60 seconds.
3. Wait 60 seconds.
4. Install the fuse.
