my heater controls don't work, the fan works fine but I can't redirect it to windshield or vents are these vacuum controls? if so I'll be darned if I can fine any vacuum hose that leads through the firewall to the controller, 1982k5

thanks in advance
Jim

I had same problem on my '84 C-10, found the line disconnected. It is a small hard palstic line going from vac pump area to the blower motor area.

Non AC have cables , AC has the vacuum line .

You might need a new vacuum pump --- with no vacuum, the air comes out of the bottom in the middle.

The pump is new, I just cant seem to find the line that feeds it to the heater control. I'll look for that small hard line that goes to the ac area

It's hard to spot but it's sort of in the middle of the firewall just toward the driver's side of the AC unit... Just follow the lines from the vacuum pump.

Well just by blind luck I found the hose,

The hose comes out of the fire wall kind of where some of you all said it might but in my blazers case its behind a plastic lining that covers pretty much the whole firewall, that hose is then routed behind all the plastic AC covers and hooks up to a round ball looking thing and a hose from there goes to the vacuum pump.

evidently the someone had taken the plastic housing off the ac unit at one time and when they put it back on they pinched the hose in behind it where I could not see it,
they also mangled the plastic cover (thankfully) as I was able to peer inside through a crack and see the hose... Houston we now have defrost

i need to rebuild my venting then see if the unit even does what it's supposed to lol

every couple years lately my 84 plugs up the selector switch in the defroster/ac selector. just take it out blow it out with low pressure air and the defroster is back.