Climate control

AK49BWL said:

Go 96+, the 95 is a ******* one-off and you probably won't even find a controller. You'll have to swap all the door motors as well. When I get back to my computer I'll throw some wires up here. Honestly tho, it'd be easier just to get a complete HVAC wiring harness from a 96+ and swap the whole thing in, then you won't have to cut and splice but maybe 3 wires overall.

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AK49BWL said:

Yes. The 88-94 control head relies on feedback potentiometers in the motors to position them correctly - the 95+ motors do all of that internally, only getting a signal input from the control head.


Wiring schematics: this ones for a 94 but all 88-94 are similar.
https://www.ak49bwl.com/other/wires/1994K1500/HVAC.pdf

For a 97, but 96-99 is the same.
https://www.ak49bwl.com/other/wires/1997K1500/HVAC-Front.pdf

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AK49BWL said:

Wiring schematics: this ones for a 94 but all 88-94 are similar.

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PlayingWithTBI said:

IIRC 88 - 91 don't have a high pressure shut-off switch (I know for a fact 88 & 89 don't), It's an "Air Inlet Valve Pressure Switch", plus there's a timer that will open the recirc door after 30 seconds when A/C is turned on and the fan is set to speeds 2 or 3. You can tell if you have this because these years don't have a recirc button, they just do it automatically. Here's the wiring for the '88 system.

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I did wire in a high pressure shut off switch by replacing the one on the back of the compressor, with one from later models (off @ 330PSi/on at 250PSI I think), and wiring it in series with the "Pressure Cycling Switch" after my system's pressure went high enough to blow that switch out of the back of the compressor - scared the sh*t out of me, ha ha.

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loosh said:

Kicking this dead horse.
I’m currently trying to put a 94 hvac system into my 88. 94 system has two high pressure cut offs, one on the compressor and one connected to the line coming out of the compressor. I can understand how to wire all that together I think, but my question is this- when I pin this system into my ecm (stock no ac 88), is it going to work? Am I going to need a whole new computer to run this ac? Is this even a question you know the answer to? Anyway glad to see at least I’m not the only one here trying to Frankenstein ac into their truck.

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