NEED HELP- HVAC control differences- NO AC
 

I got lucky enough to find some parts already off for the 72 I am working on, but i found that there are two distinctively different Heater controls for NON A/C equipped trucks. what determines what you HAD. I say HAD because mine had NONE at all in when I bought it. I see TWO cables and an electrical connector that looks too short to make it to a left side (vertical) fan speed switch.
So I guess this one takes the THREE slide controls and one of those slides has an electrical connection?? BUT it also looks like a cable is missing from underside of the heater box?? thanks, Crossy

Re: NEED HELP- HVAC control differences- NO AC
 

Here are a couple of pictures. The top cable goes to the front control arm, the middle one goes behind the heater box and to the bottom, and the bottom one goes around the heater box and into the heater box by the firewall. In the first picture you can see the switch where the connector plugs in. (I unplugged it for the picture) There are two non-A/C heater controls but the only difference is in the face that sticks through the dash. One is black and the other is silver.

LockDoc

Re: NEED HELP- HVAC control differences- NO AC
 

thank you very much- what does the face of this controller look like

Re: NEED HELP- HVAC control differences- NO AC
 

We have 2 different non AC style faces.

One is a black face, only found in 67 and 68s
The other is a silver-ish face 69-72
I've seen black knobs and chrome on the black face ones but only chrome knobs on the silver-ish faces

Re: NEED HELP- HVAC control differences- NO AC
 

http://67-72chevytrucks.com/vboard/s...heater+control '67-'68

http://67-72chevytrucks.com/vboard/s...heater+control '69-'72

Re: NEED HELP- HVAC control differences- NO AC
 

I thought they were all the same except for appearance on 67-72 trucks. LockDoc's previous post seems to confirm that. Early model had black face and later silver color. The 72 has the silver one. Some of the cars in the same era had a two lever controller that looks identical and will bolt in. Saw one a bit back. But the trucks all had three levers AFAIK. Believe the control you circled regulates the amount of heated vs unheated air to control temperature.

Re: NEED HELP- HVAC control differences- NO AC
 

The manual refers to a "deluxe heater", and of course a separate section for "four seasons", but it's a little hard to separate from all the tilt-cab and other options in the same book. Is there a standard heater, or are they all deluxe in typical GM fashion? ;-)
LMC trucking diagrams might be your clearest reference