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Climate control

Old 01-08-2019, 06:11 PM
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Default Climate control

Hello, I have a 2000 GMC Jimmy with the more basic climate control setup. I recently pulled a "computer climate control" module from a 2000 trailblazer. I was wondering if there was any way I could adapt the wiring from mine to fit that module? Or if not is there a separate computer or controller that I need? Any advice would be greatly appreciated thanks
Old 01-08-2019, 09:40 PM
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What what I remember tearing into one in the junk yard, and someone can correct me if I'm wrong, the setups are completely different.

1) Where the basic climate control unit actually has vacuum lines plugging directly into it to control the actuator flaps and direct air to various places, the computer controlled auto temp system has no such vacuum plugs going directly to the controller "head unit". It just has electrical plugs that relay info to the controller module in the dash that then opens and closes the vacuum "circuits" in the dash to move the air flow around and adjust the temperature accordingly. This means that not only are the vacuum hoses and routings different, but the dash wiring is completely different as well

2) There's also an outside temp sensor mounted to the radiator support behind the grill (separate from the one that tells you the outside temp in the overhead console display) that integrates into the system (many mistake this unused plug for a factory fog light plug when digging around behind their grill... GM for whatever reason decided to route this one single harness on ALL of the S-chassis SUV's it seems regardless what climate control setup was in them)

3) I believe the HVAC box is different between the two.

So as you can imagine, this is NOT an easy "bolt in and go" swap unfortunately... sorry to rain on your parade...
Old 01-09-2019, 02:30 PM
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I'll add that inside the auto HVAC blazers, there is a little round plastic grate/plug near where the drivers side 'oh s#it' handle would be.
Behind it, under the ceiling foam, is a sensor that the computer uses to measure temp inside the cabin.

Very technical. The best way to do the swap, is to just buy a blazer with the auto HVAC controls in it already.
Old 01-09-2019, 05:07 PM
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All that sounds correct to me plus these two things:
1) the blend-door actuator is different in the electrical plugs for them
2) and on the heater core box, instead of the heater fan resistor coils that drop in to the top f the box on the exit side of the AC evaporator, there is a solid-state temperature control module on the other fan side of AC evaporator.
Old 01-09-2019, 05:07 PM
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Oh yeah, who knows what differences there might be in the body-control modules (BCMs).
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