Setting up A/C car for Heat only

Heating / Cooling / AC

  1. Harveybos

    Harveybos Member

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    Hi
    My son & I are trying to resurrect a 73 Duster 318. It was a factory A/C car but has had the under hood A/C parts removed. The heater control valve has been replaced with a straight pipe. We’re in the U.K. so don’t need the A/C but would like to get the heater working. Prefer not to refit the vacuum amplifier if possible. The underdash vac pipes and actuators all appear to be in place but the pipes coming through the bulkhead have been cut (see pic). Are these 2 pipes the vac feed from the amplifier to A/C & heater switch, and the vac feed to the Inline heater valve? We are thinking of trying a vac feed direct, is the upper pipe the feed to the control switch?
    Thanks, Harvey

    4D9B03F9-3B9A-4F3D-B206-7C838E4EB958.jpeg
     
  2. Demonic

    Demonic Well-Known Member

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    Get some plastic plugs for that evaporator. Someone might want it. It might be easier to find a non-AC control assembly and attach a cable control valve under the hood. The trick is to have modulation - ability to control the heat proportionally.

    Yes, but I'm not sure which is which. The manifold source is connected to the vac amplifier if I remember correctly. The heat valves use vacuum to close, so without vacuum in the summer, you'll roast.
     
  3. MoparMike1974

    MoparMike1974 FABO Gold Member FABO Gold Member

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    Get a cable operated heater control valve. The AC control panel used a vacuum operated heater valve so you will have to be creative on how to hook up the cable.
    Maybe put the vents in a set position then use the vent lever to operate the heater control valve.
    Swapping in a heat only control panel is the right way to do it but they are much harder to find than the AC ones for the 73+ cars.
     
  4. 67Dart273

    67Dart273 FABO Gold Member FABO Gold Member

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    I may have misread the above^^ but a heat only control panel does not control the coolant. Only AC cars had a valve.

    I would attempt first to check out and get the AC controls working. They will operate the system fine if so.

    OP: You have a factory manual? You can download it free at MyMopar. That and other ones got there because of some of the guys right here. There are two volumes, the Chassis and Body manuals.
     
  5. lemondana

    lemondana BlackDart

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    I would round up all of the AC stuff and reinstall and be cool.
     
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