: Climate Control Swap from later box Brougham to 79 Deville

06-23-11, 04:23 PM
How much more reliable how the climate control systems in the later 80s to 92 Broughams? I have problems with the blower relay in my 79 that I still haven't gotten around to fixing, and I know a lot of other people have too. Some have fixed it with a manual fan control knob mounted under the dash, but I don't really like that solution. I would rather have full manual control over the entire system that looks stock, or swap to the Brougham system. I know Audi also used the Cadillac system in some of their models around the late 80s early 90s, so it must not be too bad. Obviously it will be a pain to do, with the wiring and vacuum lines, not to mention maybe having to swap the vent doors etc. Maybe I should just have a stripped down Caprice or Crown Vic since they're probably simpler.

06-23-11, 05:15 PM
The '80's digital system is more reliable and there are no relays to fail. The only real reliability issue is that the newer ECC relies on three components (the digital control head, the programer, and the power module) and if any one of those starts having problems, the entire system goes out. Because of this, the ECC is harder to diagnose, but if you can find the malfunction, the fix is simple and relatively permanent.

Retrofitting your system to work with a digital ECC might not be that simple; I don't think anyone on here has done that. If you have a wiring diagram for the '79 climate control, you can compare it to a diagram from an '80's Cadillac to see how difficult it would be.

06-23-11, 05:51 PM
Do all of the 80s ones have the same ECC system?

06-23-11, 06:40 PM
They started using the digital one in '81 and put the same system on both the Fleetwood Brougham and de Ville models. The Eldorado and Seville had a similar system, but I don't think it was the same. In '85 the de Ville and Fleetwood models were moved to the Front Wheel Drive platform and the interior electronics were updated, but the Rear Wheel Drive Brougham continued using the same ECC setup up until 1989.

So basically look for parts from any RWD Cadillac made after 1980, but before 1990.

06-24-11, 03:06 AM
Sweet, thanks man.

09-23-13, 12:10 AM
Hey Ferrisworld,

Did you end up doing this swap? I'm in the middle of getting parts together for my 78 fleetwood. I thought I heard somewhere that these units tied into the computer also? Is this true? I'm assuming all you really need is the outside temperature sensor, ATC programmer, climate control head, interior sensors and the temperature sensor on one of the heads of the engine right? I am getting ready to run to the salvage yard this week to pull this setup from an 87 brougham. Any help from anyone is appreciated. I'm just trying to figure out how to strip it from the huge wiring harness to other stuff. One other thing i'm wondering about is the rear defrost. On my car I have a switch for it and on the 80's broughams it's hooked up to the climate control head assembly it looks like. Has anyone on this board done this kind of swap?