going from a digital to analogue HVAC controls

Discussion in 'OEM and Custom Interiors' started by KRS1, Oct 22, 2018.

  1. KRS1

    KRS1 OBS Enthusiast

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    Hey guys, I have '88 C3500 that I will be re-doing all the wiring etc. I will be using the Speedway 22 circuit wiring kit...

    https://www.speedwaymotors.com/Speedway-Universal-22-Circuit-Wiring-Harness,229874.html

    I currently have the digital controlled HVAC system. I was at the 'yard on the weekend and saw that you would also get the older style controls in our trucks. How hard would it be to do this?

    I would put power to the fan switch. Other than that; the steel wires would have to connect the ductwork etc..I just recall that in my '70 Chevrolet Monte Carlo (before it became a drag car) it wasn't too complicated..
     
  2. 454cid

    454cid I'm Awesome

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    Do you have AC? Wasn't that other system heat only?

    If that's not a problem, seems like a good idea, to me.
     
  3. KRS1

    KRS1 OBS Enthusiast

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    Hi 454, I have AC but I am going to delete it..Someone pulled the engine etc before I bought it and I think scrapped a lot of the AC components.

    .I figure later down the road I will install something. Perhaps even use the stock system somehow. .I will be sweating up here though in Canada! global warming..
     
  4. someotherguy

    someotherguy I'm Awesome

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    If you think you're ever going to put A/C back in it, I'd suggest sticking with the factory controls and wiring. He is correct that the manual setup is for non-A/C trucks.

    The A/C system really isn't complicated or difficult to put back in (on a truck that was already equipped) so giving up on it and gutting the rest just leads to more work later.

    Not sure why you're doing an aftermarket harness unless your truck no longer has the original engine management setup.

    Richard
     
  5. KRS1

    KRS1 OBS Enthusiast

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    Thanks Richard, yes the wiring system now has been hacked a lot and I just want a more simple system in it..a HEI and a carb, I already have both and I am experienced in setting up a system like that with working on the Monte..
     
  6. Mike Duckworth

    Mike Duckworth Newbie

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    Let me know if you want to sell the digital a/c and heat 5 button controller, I need one. Thanks, Mike.
     
  7. KRS1

    KRS1 OBS Enthusiast

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    Hey Mike, yes when I remove it I will do it carefully.
    I went to the yard and found a old tow truck with the AC delete option. We started to remove the dash pieces to get a look at it..I assume that I will need the old heater (non AC) box as well? It looks like there are a few wires going to the box. I assume one is for the fan (hamster wheel)lol, I wonder what the other is for?
     
  8. someotherguy

    someotherguy I'm Awesome

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    Really haven't worked on/seen many non-A/C trucks down here in SE TX as you might imagine, but the wires going to the non-A/C heater box should be power and ground for the blower motor, and also a harness to the blower motor resistor and associated relays.

    Richard
     
  9. KRS1

    KRS1 OBS Enthusiast

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    Thanks again Richard, yes I have a cousin he lives in Houston and AC makes a big difference. Although with global warming we are getting days in the 90's up here..
     
  10. 7thdarkangel

    7thdarkangel Just a guy with tools

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    I just did the opposite. When from non ac to ac. Currently have the whole non ac box and control set up in the attic.
     

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