Got another piece of the puzzle done this week! We now have AIR CONDITIONING!!!!!
I absolutely hate being hot so I’ve built different universal AC kits in the past and I have been planning on installing one in this build since the first 90* soggy day I drove it last july. I want to be able to hop in this thing any given nice day and enjoy driving it to work or on a weekend cruise and be comfortable. So heres the lowdown......
After much reading, comparing, measuring, and reviewing I decided on using the vintage air mark-4 underdash unit and keeping my stock recirculating heater that I already put the upgraded core/spal fan in. It works great and fits the “stock appearing” theme I’m goin for. Funny enough I found limited reviews on people that actually used one. Lots of “I heard’s” and 2nd,3rd, 4th hand accounts of their performance and fit. Then reading in summit I see a picture of the one guy that actually put one into a AD truck and it looked like it fit great! So I measured 20 times before ordering and I knew I would need to move my heater over more to pass side to clear the AC unit but I wasn’t at all bothered by that. The rest of the pieces I sourced from my normal ebay spots that Ive had success with previously. I already own the hose crimping tool so I was already prepared there. I bought a universal 17x19” condensor and the universal hose kit with reciver drier with a trinary switch then a SD7 style compressor and the fittings to adapt it to normal #8/10 hoses. I normally build my own bracket for the pump and run it on a separate belt on the inner belt on LS setups but I actually found a really nice bracket setup that moved the alternator into a better spot for me and ran the AC on the same 6rib belt and used a factory automatic tensioner. It was cheap enough where I knew it would save me enough time and aggravation lining up pulleys and swearing and anger so I just bought it.... 100% glad I did too because it was perfect. So thats all the parts, now onto the installation!
Mounted the underdash unit without drilling a single hole in the dash! Used the inner screw for the ignition switch on left side then used the existing hole on right side for the stock heater temp rod on the deluxe heater valve setups. Used the provided strap mounts and cut and bent until they worked. The unit is very close to flush to the dash and I positioned it so it does not at all effect the cowl ventðŸ‘. The fittings actually lined right up with the 2 factory holes in the firewall too! I did slightly enlarge one to pass the hose fitting through but it was minimal. The one holes I did drill was way up on the firewall to mount the strap to hang/support the rear center of the unit and a hole by the floor for the evaporator drain hose to the ground. My next task was mounting the condenser in front of the radiator. That was very easy with the included universal brackets. I ground the lip off the rad support where the brackets landed and then it was just 4 sheet metal screws and I put foam tape on the entire perimeter of the condenser and sealed it to the rad. This helps force air through everything rather than around it. Then I mounted the receiver drier just behind the grill to the front part of the inner fender. When laying out and planning all of this you need to account for where is the easiest/best/shortest way to run all the hoses. I decided to shoot the hoses through the front of the inner fender and have them pass back into the engine compartment right next to the compressor from the inner fender. I made it look as clean as possible. Next was compressor mounting. That accessory drive setup was a easy bolt on deal as expected. Only thing left now was to run hoses. So I ran all hoses in their spots and cut them and crimped the 8 fittings I needed to complete the loop and all was good (or so I thought). So I figured i was done there and moved onto wiring. Wiring the AC unit itself was simple. I put it on its own relay because they say between the compressor clutch and blower it can draw up to 20amps. The tricky part was wiring the electric fan so It was still controlled by the factory PCM but would also turn on via the trinary switch without effecting the PCM. I did this by just running a isolated relay so not to effect my original fan relay controlled by the PCM. Works great ðŸ‘. So now I hooked up my vac pump and sucked it down assuming I would be ready to charge it up with my manifold gauges and adapters and the 12oz refrigerant cans that I use to feed it. Well those gauges fell to zero in about 3 min. WTF!? Leaks! So after scratching my head going over every o-ring and hose I was at a loss. Vacuum leaks are hard/impossible to find on a AC setup so I opted to just jam 120psi shop air into it. Not optimal as far as moisture but it is very effective. Found 4 leaks at my crimps. Not sure why but the way the tool is designed it gives you a “finish line” to stop at so you dont over crimp a fitting. Well the larger lines wanted to be bottomed out so thats what I did and it fixed all 4 leaks. So i fired up the pump again and it was good. Vacuumed it for a hour and let it sit overnight since it was late. It held! Charged it with 28oz the next day and Im pleased to say it basically will make my hand numb. It hasnt been hot out yet but today was almost 70* ambient and in the sun the 5 window greenhouse effect cab was instantly cool. My one last thing to install now is the cable operated heater valve (that i will most likely actuate via factory choke knob) that will recirculate back to the engine and keep the heat out of the cab. I also have insulation and floor mat to install still. All in all its a success.
Now I have what appears to be a factory stock truck from outside and the interior (besides the era correct AC) BUT...... its actually powered by a 285hp fuel injected GM V8 with era correct electric overdrive and AC. I will include below the parts list / price of the stuff I used. Mostly all universal stuff found online and the vintage air underdash unit straight from summit racing online. Enjoy...... I am !!
Vintage air underdash AC $305 Universal 17x19” condenser $65 Hose and drier kit $80 Compressor $150 Mount kit for my application $200 Trinary switch $18 Heater valve (to stop/recirc flow) $50 GRAND TOTAL of $868 Having frosty nuts on a 100* day =$ PRICELESS
I could have easily saved myself the $200 on the mount and made it for free and kept the cost in the $650 range but I was sick of fabbing and wanted a break.
