i recently tore out all the old a/c stuff from my 79, and i'm looking to replace it with factory heater equipment. Any advice or tips to make this install easy would be greatly appreciated
I went from non-a/c to a/c when I did my engine swap. It was fairly easy to work on without the fender and hood in the way. I lined up the outer box with the fan and drilled new holes for the mounting bolts, then went back and covered the holes for the heater core and cut new ones; then I installed the inner box/ducting. I'm still going to have to redo it when I'm ready to paint the truck as I only had the weekend to swap the engine and its my daily driver, but until then it works.
ya as far as i know, i'll have a lot of hole patching to do on the fire wall. one of my many questions, is there any major difference between the ducting for a/c and standard heater/defrost?
I have a few pictures of the a/c that was on my 86 that might help. As far as the a/c duct work, the a/c side has is own vaccuum canisters for the vents, vaccuum storage devices and lines, control panel, fuses and relays to deal with.
To start the glove boxes are different but you can still use yours if you want. You will only need the the main center duct and the part that hooks up to the None A/c blower. And yes there is a few hole blocked off or made in new places .
Standard heater does not have the 4 dash vents like a/c, just the 2 defrost by the windshield and the vent below the dash over the trans tunnel. It is also controlled by 2 cables rather than one cable and the vacuum controls. The 2 vents in the kick panels are also controlled manually by a pull lever. Here are pics of standard heater on my truck just before I pulled it. Looks like I didn't take any pictures of what I did to the firewall before I installed everything. The heater core hoses went through right where I had to cut for the evap core, and the duct hole is closer to the fan. The mounting bolts did not exactly line up between the two, although all I really remember is that the far passenger side bolt did not line up.
I think the best way to achieve that would be to cut the a/c box in the engine bay just past the heater core hoses, then fabricate some sort of duct that goes from that to the hole for the evap core. You could also try cutting a standard heater inner box where the a/c ducting attaches behind the glove box, but I don't think it would work too well since it wont be set up to divert the air. The standard and a/c setups are just too different to mix and match, really; the only interchangeable parts are the fan, and the defrost ducts.
