'96 dash upgrade in '94 blazer but the hvac control has me stuck

[GMsoulmate]

Hey everybody - I've always found so much info in these posts and want to say thank you for so many answered questions without ever posting one of my own.
Ive got a 94 K1500 Blazer resto project that I'm just about in the final days of completing (sure, but.....) and i have not been able to get much info or experience in the wiring from the 94 digital control to the 96 analog style specifically the mode and blend motor/actuator difference. Can I use my existing 5 wire "motors" with the 3 wire "actuator" control wires or is there a wiring hack to make that work? I know the part #s are different for those but can i just swap them out using the 96 actuators or do i actually have to replace the entire hvac housing?
THANKS for your help!

 

[GoToGuy]

Are you using the 94 and 96 OE service manuals that have the OE wiring diagrams? It's a digital display. Not digital control. I would first compare the wire digrams to see if the HVAC module circuits can be repinned into the new connectors for 96 control head.

 

[AK49BWL]

They cannot. You can swap an entire HVAC harness and actuators out of a 96+ truck into your truck with only a couple splices (power, ground, illumination, A/C). But the 88-94 and 95+ actuators are NOT compatible with the opposite's controller.

88-94 door actuators use the five wires to receive power and send their "location info" to the digital head unit via an internal resistor, the head simply sends voltage to the motors to try to get a change in the returned resistance values. The 95+ door actuators have only three wires each; the locating resistance circuitry is built into the actuators themselves, and receive a variable voltage from the control head to determine what position they should be in. For that reason, all three mode doors, wiring harness, blower resistor block, and controller have to be swapped if you want to go to the 96+ controller.

Source: I went the opposite direction.

 

[GMsoulmate]

Thank You so much for that info. I have the diagrams for both but I now have the understanding beyond the drawing, which of course the service manuals dont explain the differences for doing a dash swap. But your shared knowledge makes it easy-peasy for me and anyone else who reads this. TY! TY! and btw , your truck is probly awesome - my build has the manual 5spd 4x4 which I rarely see and was the main reason I got the truck. ( I still dont know how to drive an automatic, lol)