99 HVAC upgrade
Thread Starter
Instructor
Joined: Nov 2016
Posts: 244
Likes: 103
From: Pueblo West CO
99 HVAC upgrade
My C5 started life as a base m6 coupe. It's a had a lot done to it, mostly in the driveline. I've swapped to a double DIN console and head unit, but I still have the base HVAC controls. I know many of these C5's came with actual climate controls and I assume I'm not the first to think it would be nice to upgrade. What is involved in this upgrade?
Administrator
Joined: Mar 2001
Posts: 368,360
Likes: 24,783
From: In a parallel universe. Currently own 2014 Stingray Coupe.
C7 of the Year - Modified Finalist 2021
MO Events Coordinator
St. Jude Co-Organizer
St. Jude Donor '03 thru '26
NCM Sinkhole Donor
CI 5, 8 & 11 Veteran
Moved to C5 Tech.
Safety Car
Joined: Mar 2017
Posts: 3,771
Likes: 940
From: Orlando Florida
I have not done it, nor have I seen any write ups for it, but a decent understanding of the components involved indicates it’s a lot.
In addition to the digital controller, the air handler — the big black plastic assembly that takes up half the area under the dash — is different, with two separated blend doors instead of one common blend door. You’ll have to add multiple sensors under the hood and in the dash, plus the wiring to those sensors. Compressor, condenser, accumulator, and refrigerant lines should be the same, but would take some research.
In addition to the digital controller, the air handler — the big black plastic assembly that takes up half the area under the dash — is different, with two separated blend doors instead of one common blend door. You’ll have to add multiple sensors under the hood and in the dash, plus the wiring to those sensors. Compressor, condenser, accumulator, and refrigerant lines should be the same, but would take some research.
Tech Contributor
Joined: Jan 2007
Posts: 19,465
Likes: 1,167
From: Dyer, IN
Most just buy a C5 with auto climate control...they are plentiful, and available in every color. 
The complexity really depends on two things: 1) if the ducting and evaporator configuration is common, 2) if the interior wiring harness is common.
