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Old 01-04-2018, 11:44 AM   #51
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Join Date: Nov 2017
Location: West Chester, PA
Posts: 4
Re: Installing Air Conditioning in a 71

Hi all,

I was really struggling to get my heater control panel installed and figured I write up my findings and maybe others have tips or an even better procedure? Again I'm not claiming this is the proper way of doing things but after several failures, this way worked for me:

1) I took the airbox pieces inside the cab off (except for the big one that has the heater core in it and is bolted to the firewall) I left the pieces screwed together (metal end unit + S-shaped plastic piece + piece that connects to heater core-box)

2)I put things on my workbench and test-connected the cables to the control and levers on the air boxes:
-Short cable: Goes to the backside of the airbox onto the lever with the switch for the ac compressor. It connects to the middle lever on the control panel
-Medium cable: Goes thru the firewall to the lever on the outside box. It connects to the bottom lever on the control panel.
-Long cable: Goes to the front lever at the end of the inside air-box. Other end connects to the top lever on the control box.

3) I tried all heater control levers and adjusted the length on the cables to make sure the flaps inside the air-boxes are moving proper from one end to the other. The little metal clip on the cables can be screwed in and out on the exposed steel sleeve of the cables. That's how you adjust the length of the movement of the cable when the control lever is moved on the control panel.

4) I connected the vacuum hoses onto the control panel switch.

Now it was time to get things installed:

1) I removed all ductwork behind the dash. My first attempt was with the ductwork in place and there was absolutely no room to push the control panel into the opening. In fact I bent my control cables so badly...

2)I kept the short and long control cables connected to my inside airbox-assembly. Especially the short control cable is nearly impossible to install onto the airbox, once the box is in place so I had that connected prior to putting the box in. The control panel end of the short cable is disconnected for assembly. Only the long cable stayed connected to my control-panel

3) I connected the 2 electrical cables to the ac-compressor switch on the backside of the airbox-assembly.

4) I put the airbox-assembly into place and secured it with the 2 bolts onto the heater box and the one bigger bolt onto the center of the firewall.

5) Now I connected the electrical onto the control panel and slid the control panel into place and secured with the two bolts from the bottom of the dash.

6) With the control panel in place, I connected the short cable to it. It's tight but doable.

7) I routed the medium control-cable through the opening in the firewall. Then I secured the control-panel end first and afterwards secured the other end inside the engine compartment.

8) With all control-cables connected, time to check for proper operation.

9) Now comes the tough part (at least for me it was): Put all duct work into place. Honestly, I was pushing, pulling, sweating and swearing so much while getting all the ducts into place and connected...I cannot recall the final order in which I was able to get them all in...but it is tight...I used the LMC plastic ducts with metal spirals in them. They are very robust but their rubbery material is kind of sticky when you try to route them around in the tight space...

10) Moment of truth: Turn the fan on and move all levers to see if you get the air coming out where it's supposed to be ;-)

Wish I had taken some pictures but I was cursing so much with all the different attempts I took that picture taking was not really on my mind ;-) ...

I'll be putting the actuators and vacuum lines into place in the next days and post about that...
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Old 07-16-2018, 01:18 AM   #52
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Join Date: Jun 2018
Location: Louisiana
Posts: 123
Re: Installing Air Conditioning in a 71

Since this thread is several years old, I'm wondering if you all could help.
I just purchased my first truck, a 72 with out factory ac. I need some air here in Louisiana!! Does anyone have any advice on how to go about adding a good system to my heater only truck?
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