front climate control replacement?
- Thread starter DMD_TB
- Start date
Blacktrails
Member
- Dec 8, 2011
- 34
No theres alot more to it then that. I don't know all the details but i know that it involves replacing the entire HVAC system. Sensors, controls, vacuum hoses. It can be done but its not very practical.
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Blckshdw
Moderator
No vacuum hoses, but yeah it's too expensive and time consuming to be worthwhile. I know of 1 guy who did it on the OS, that's about it.
You can find cheap used ones for replacements on Ebay, just make sure there's a picture of the unit. I had to replace mine (due to a botched LED mod) and the ad I found didn't have a pic on it, just the description and RPO code. The one they sent me did NOT have the rear defrost button on it
so I had to send it back and get another one. 
You can find cheap used ones for replacements on Ebay, just make sure there's a picture of the unit. I had to replace mine (due to a botched LED mod) and the ad I found didn't have a pic on it, just the description and RPO code. The one they sent me did NOT have the rear defrost button on it
so I had to send it back and get another one.
Blacktrails
Member
- Dec 8, 2011
- 34
. There must be a lot more to the manual ones compared to the digital ones? my digital was just a plug in back of it.
Blckshdw
Moderator
itstrick said:
You got it backwards. It's not just the digital/manual module, but the digital one has an ambient air temp sensor in the driver's side B pillar, manuals don't. There's all the wiring associated with that sensor, also the exterior ambient air temp sensor behind the front grille (some models that do not have the outside air temp in the rear view mirror would have to add this as well)
Plus 5 additional temp sensors in the ductwork for closed loop feedback that the manual system doesn't have, plus a left/right sunload sensor in the little dome at the front center of the dash so it knows which side of the car the sun is shining on, plus the blower speed control module is the more expensive continuously variable one instead of the 5-speed discrete resistor pack. That's what makes the wiring harness upgrade so painful. Without a donor vehicle and access to factory schematics, it's an expensive or impossible mod.Blckshdw said:
the roadie said:
I will be making the attempt in the near future. Does anyone know the member's name from the OS that did the conversion? Did he post up any information on how he did it?
I forget the name, but it was an Envoy. Sorry, not going to search the OS. He said it took access to the factory manuals and schematics, and was not worth the effort except as a technical challenge that nobody had ever attempted. The cost/benefit ratio is pretty small. I have the shop manual and schematics, and predict you'd have to spend $300 on parts alone, even using Ebay for the speed control module and the head unit. You'd need a lot of Delphi connectors to make your own harness. And disassembling the dash is not for the faint of heart. Without compnine available for exploded parts views, you'd also need that sort of resource, or a donor vehicle to look at as you disassemble it in the junkyard.91RS said:
- Dec 4, 2011
- 75
Blckshdw said:No vacuum hoses, but yeah it's too expensive and time consuming to be worthwhile. I know of 1 guy who did it on the OS, that's about it.
You can find cheap used ones for replacements on Ebay, just make sure there's a picture of the unit. I had to replace mine (due to a botched LED mod) and the ad I found didn't have a pic on it, just the description and RPO code. The one they sent me did NOT have the rear defrost button on it
Ok thanks a ton guys definitely not worth it
the roadie said:I forget the name, but it was an Envoy. Sorry, not going to search the OS. He said it took access to the factory manuals and schematics, and was not worth the effort except as a technical challenge that nobody had ever attempted. The cost/benefit ratio is pretty small. I have the shop manual and schematics, and predict you'd have to spend $300 on parts alone, even using Ebay for the speed control module and the head unit. You'd need a lot of Delphi connectors to make your own harness. And disassembling the dash is not for the faint of heart. Without compnine available for exploded parts views, you'd also need that sort of resource, or a donor vehicle to look at as you disassemble it in the junkyard.
I'm not worried about that. I've access to all those things. I've also taken a few instrument panels out, I even took the carrier out on one to fix a rattle from the heater core. I'm also adding steering wheel controls so I may do both at the same time. It looks like I need to rewire the the recirc door actuator so I might as well replace the ducts with the sensors rather than drilling holes since the dash has to come off anyway. I can't stand the manual A/C, I had auto A/C in my 02 (as well as the steering wheel controls) so it's worth it to me.
IIRC, only the '02 offered HVAC controls in the steering wheel. Might have to research that a bit. No idea why they stopped the option. Maybe the folks who had the automatic HVAC were also getting the DIC and you can't have DIC, HVAC, *and* audio controls all on one steering wheel?
the roadie said:
2002-2003 had the HVAC controls in the steering wheel. Another thing I'll miss about my 02. I may look into adding that too since that button goes to the BCM and the BCM sends a Class 2 message to the HVAC module, so unless the programming is gone for that button I may be able to add that. I don't care about the Onstar buttons.
Blckshdw
Moderator
Blckshdw said:
No, the Onstar buttons replaced the HVAC buttons. The upper left button controlled fan speed and temperature on the 02-03 wheel, but after that it changed to Onstar.