Ok fellas... wanna run this past you guys. I recently got a Heat/Air underdash unit from a buddy. No other parts, is it as simple as going to the salvage and getting the rest of the parts and hooking it up?? This underdash unit came with a condenser, drier canister, and compressor only... no I only got the underdash piece no other parts. I picked up a compressor from another friend so I'm hoping all I need is a drier and a condenser and I'm set! Appreciate the help here!!!
Don't use junkyard parts. New is cheap enough. Measure for the condenser up front, then find one that will fit your space. Sanden 508 compressors can be had for under $200. Find a hydraulic hose shop in your area and inquire about hoses and fittings, they will also crimp for you. Driers are cheap also, never re use one from a junkyard.
Dont forget to put in a pressure switch to protect the compressor. Binary switch for mechanical cooling fan & trinary switch if you are using a electric fan. You will also need some #6, #8 & #10 barrier hose & some charge ports if they are not already on back of compressor. I would get a drier that has the port for the pressure switch. Vintage Air has a nice diagram online or I can email you one. I just went through this for my Model A. Its not too tough.
I've done it both ways - with used stuff and a Vintage Air set up. Of course the VA was WAY easier partly because (as sy1356 said) there's a lot to getting the binary switches ad vacuum relays to work properly, as well as the AC pump to kick in and out correctly - unless you try to do it all manually.
shop manual for a random olde car of your make with ac to get wiring diagram for easy hook up of proper pressure switches, would be a good cheap investmant at this point, this will also show proper plumbing diagrams
Are used compressors ok? I'll look up the VA diagrams and if it don't make sense I might just pm you! Good idea... our other local place has had some complaints about AC lines they made leaking!! Would like to do VA but, this whole build is on a budget!! That's a great idea! That's my backup plan!!!
Does you underdash unit have an expansion valve? Make sure you flush the evaporator in case there is trash from the previous system. I'm a vintage air dealer, and installed loads of systems, installing a new compressor might save a lot of time and money in the long run, the late model compressors are pretty reasonable
If your unit is a newer aftermarket one, it might have an orifice tube, if it is one of the old ones from yrs. ago, it probably has an expansion valve. If newer and has a brand name you might want to post it, or google it for more information. If used, I would for sure flush everything good and go with a new drier.
On my COE I used the underdash unit from an 87 Dakota. On one end are the heater hoses and the other side has the expansion valve. Usually the fitting off the expansion valve points to the outside of the vehicle, I had to have a custom built one to point towards the center. After that, I needed a dryer and hoses. I used a Sanden compresor, custom built hoses and the largest condensor I could fit behind the grill. The controls on the dash are from the dakota and they shut off the hot water via a vacuum operated valve. The unit even has a recirculate function (thus the fresh air vents on the firewall). There is a trianary switch in the system too.
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