Not blowing cold air

Heating / Cooling / AC

  1. DentalDart

    DentalDart Well-Known Member

    Messages:
    2,388
    Likes Received:
    1488
    Joined:
    Jul 5, 2019
    Location:
    Las Vegas
    Local Time:
    3:40 AM
    Ok so my compressor works (I think), my air blows just not cold (besides today because it's cold outside) and my clutch on my compressor engages.

    Would this mean I just need to charge the system? I tried charging it before, doing the whole page oil then filling with R134A but it didnt work.

    Any ideas? I'd love to have A/C this summer
     
  2. Murray

    Murray FABO Gold Member FABO Gold Member

    Messages:
    1,643
    Likes Received:
    1062
    Joined:
    Apr 19, 2010
    Location:
    San Jose, California
    Local Time:
    3:40 AM
    Usually that is what it means. Am concerned that you may have a leak. I think better "O" rings are needed with R134. A dye is put in the system to find leaks.
     
    • Like Like x 1
    • Agree Agree x 1
    • DentalDart

      DentalDart Well-Known Member

      Messages:
      2,388
      Likes Received:
      1488
      Joined:
      Jul 5, 2019
      Location:
      Las Vegas
      Local Time:
      3:40 AM
      So maybe I should look for some R12 or dye that would help determine if I have a leak.
       
    • Joey4speed

      Joey4speed FABO Gold Member FABO Gold Member

      Messages:
      571
      Likes Received:
      378
      Joined:
      Jul 17, 2018
      Location:
      Jersey
      Local Time:
      6:40 AM
      There are two ways to do this: To do it correctly, need to draw the system down to evacuate it and hold a vacume for awhile, if it wont hold a vacume, the system is not tight and has a leak. You will need the guages and a vacume pump for this.
      Assuming theres no leaks, (if you cant hold a vacume, partially charge system with a dye) If the system is tight, add the proper amount of refrigerant without releasing the vacume. Too much freon will also cause a warm air condition. The compressor will cycle on and off intermittently when operating normally.
      The car has Low and Hi psi sides. The larger diameter lines on the car is Low, the smaller lines are high side psi. (The pressure drop makes the freon cold at the Thermal expansion valve at the firewall, you can feel the cold pipe when its working properly). Always add freon to the Low side.
      Note: The guages have 3 hoses, Red for Hi, Blue for Low and the third hose (can be any color) is for accessory, like a vacuum pump or adding freon. Each guage has a valve, opening the valve will allow the 3rd hose direct feed (or draw) from the accessory hose. All freon is as added to the Low side guage. This guage is a compound guage and reads inches of mercury (hg) past 0 psi, (negative psi or vacume).
      Its a doable project, if you have the right tools.
      Now that you know the theory:
      If you dont have the tools, check for leaks with a dye and remember, the evaporator (like a heater core) can be leaking inside the dash). If you add refrigerant w/o a sealed vacume tight system, it may work, but never as cold as it is capable of blowing.
      Good luck.
       
      • Agree Agree x 2
      • Arron tate

        Arron tate T B L

        Messages:
        384
        Likes Received:
        304
        Joined:
        Sep 12, 2018
        Location:
        USA
        Local Time:
        6:40 AM
        Hello DentalDart,
        What are we working on? (year, make, stock or aftermarket AC)
        Please read and understand what Joey4speed added in his post,
        Then can you do the following?
        Can you provide a pix of the under hood?
        First step is to put a set of gauges on the High and Low side.
        What are the reading with the engine off? Note: take readings after the engine / compressor has been off for 10 minutes. If there zero stop and let us know.
        Both high and low should be approximately the same (equalized).
        Second step. With gauges still connected to the High and Low side run the engine and put the system into max (full cool) and confirm the compressor crank shaft (not only clutch) is turning (nut in center of clutch).
        What is the reading on the gauges at this point? The high side should be over 100 Psi and the low should be under 50. NOTE: The readings will differ with ambient temp and inside car temp. Psi readings I am given are for example only but should be a starting point.
        Third Step.
        Questions,
        With engine running and the system off (all slide control's and fan off on dashboard) when selecting heat Or ac do you here the damper doors in the heater / ac under dash box moving? (vacuum sounds).
        With the system in Max / Full cool is the fan running in high speed?
        With the compressor running does it cycle on and off? if so how often?
        If so what are the gauges doing at this time?
        If the high side is above 100 Psi and the low is under 50 psi with system running carefully (use inferred gun if possible) check the following.
        Temp of inlet hose to compressor?
        Temp of outlet hose to compressor?
        Temp of inlet hose to condenser?
        Temp of outlet hose to condenser?
        Temp of inlet hose to filter dryer?
        Temp of outlet hose to filter dryer?
        Temp of inlet hose to evaporator?
        Temp of outlet hose to evaporator ?
        Temp of inlet hose to expansion valve?
        Temp of outlet hose to expansion valve?
        Note: The temp readings you are taking and supplying don't need to be scientific just as best as you can get them.
        Perform the above tests and let us know the results so we can further help you.
        Happy Mopar :)
        Arron
        Edit = clarification of description.
         
        Last edited: Mar 21, 2020
      • Murray

        Murray FABO Gold Member FABO Gold Member

        Messages:
        1,643
        Likes Received:
        1062
        Joined:
        Apr 19, 2010
        Location:
        San Jose, California
        Local Time:
        3:40 AM
        My knowledge is limited but my understanding is that R12 is illegal and not available. You will be dealing with R134. Here is a photo of the proper gauge, a two gang is more common. Has been too long from the trade to offer much advise. The help so-far has been good. 100_2625.JPG
         
      • Dana67Dart

        Dana67Dart Like a fine wine, only getting better with age! FABO Gold Member

        Messages:
        4,128
        Likes Received:
        2497
        Joined:
        Jul 16, 2017
        Location:
        Northern Colorado
        Local Time:
        4:40 AM
        doubt you will find R12 not to mention it would be prohibitivly expensive.

        Did your system ever work?
         
      • DentalDart

        DentalDart Well-Known Member

        Messages:
        2,388
        Likes Received:
        1488
        Joined:
        Jul 5, 2019
        Location:
        Las Vegas
        Local Time:
        3:40 AM
        It never blew cold air.
         
      • DentalDart

        DentalDart Well-Known Member

        Messages:
        2,388
        Likes Received:
        1488
        Joined:
        Jul 5, 2019
        Location:
        Las Vegas
        Local Time:
        3:40 AM
        Thanks for this, I dont have the correct guages and a/c tools to do it the first way mentioned. Maybe I can find some on in the local fs ads though.
         
      • toolmanmike

        toolmanmike FABO MODERATOR Staff Member FABO Gold Member

        Messages:
        48,647
        Likes Received:
        33317
        Joined:
        Jan 18, 2006
        Location:
        Iowa
        Local Time:
        5:40 AM
        Or take it to a mechanic that has the correct tools. Is it a R12 system converted to R134a? That can cause some performance issues right there.
         
        • Agree Agree x 2
        • DentalDart

          DentalDart Well-Known Member

          Messages:
          2,388
          Likes Received:
          1488
          Joined:
          Jul 5, 2019
          Location:
          Las Vegas
          Local Time:
          3:40 AM
          69 dart with 68 340 engine. Stock ac setup.

          Heres pictures and video. Should I replace the dryer since I tried putting R134A in it?



          20200321_101729.jpg

          20200321_101742.jpg

          20200321_101751.jpg
           
        • DentalDart

          DentalDart Well-Known Member

          Messages:
          2,388
          Likes Received:
          1488
          Joined:
          Jul 5, 2019
          Location:
          Las Vegas
          Local Time:
          3:40 AM
          This is the more expensive option:poke:.... but most likely the smartest option.
           
          • Agree Agree x 1
          • MOPAROFFICIAL

            MOPAROFFICIAL FABO Gold Member FABO Gold Member

            Messages:
            5,480
            Likes Received:
            4459
            Joined:
            Jun 1, 2016
            Location:
            Beach
            Local Time:
            3:40 AM
            That and make sure the heater door is closing and not blending hot air into the mix.
             
            • Agree Agree x 1
            • Arron tate

              Arron tate T B L

              Messages:
              384
              Likes Received:
              304
              Joined:
              Sep 12, 2018
              Location:
              USA
              Local Time:
              6:40 AM
              Hello DentalDart,
              See if at lease you can get us the High and Low Psi when not running and when running. Some auto stores loan gauges or check with a friend. This will at least help us get you in some direction before you replace anything or take it to someone.
              When the compressor is running is the high and low sides at least warm or cool to the touch?
              Let us know,
              Happy Mopar:)
              Arron
               
            • lemondana

              lemondana BlackDart

              Messages:
              394
              Likes Received:
              198
              Joined:
              Dec 7, 2007
              Location:
              Southeast NE
              Local Time:
              4:40 AM
              R12 is not illegal and it is available. You just have to know where to look. I just bought 4 cans at our Lincoln Swap Meet a couple weeks ago for 10.00 a can. I have never seen an old R12 Mopar system that has been converted to R134 work worth a damn! Ask around, there is always some around, garage sales, always swap meets or someone like me that has about 75 lbs.
               
              • Agree Agree x 2
              • Like Like x 1
              • DentalDart

                DentalDart Well-Known Member

                Messages:
                2,388
                Likes Received:
                1488
                Joined:
                Jul 5, 2019
                Location:
                Las Vegas
                Local Time:
                3:40 AM
                This sounds like it would be a smart thing to do. Can I ask a question? Where is the heater door? Lol. :)
                 
              • Demonic

                Demonic Well-Known Member

                Messages:
                1,177
                Likes Received:
                918
                Joined:
                Mar 21, 2015
                Location:
                Maryland
                Local Time:
                6:40 AM
                A/C service is something that requires a high degree of precision. You drained, flushed the compressor of all mineral and added polyalkylene glycol a.k.a. PAG with out replacing the dryer? A recipe for failure for sure. If you left any mineral oil in the system it's worse. Poly Ester oil is compatible with R12 and R134a and is much better suited to vintage retrofits. It is readily available in most auto part stores.

                https://www.autozone.com/a-c-chargi...er-refrigerant-oil-with-ice-32-8oz/117707_0_0

                Find a commercial AC tech who will most likely have nitrogen in his truck. Pressure test the system with nitrogen. Fix all the leaks. Evacuate properly and charge with approx. 80% of the original R-12 charge.
                 
                • Like Like x 1
                • Agree Agree x 1
                • DentalDart

                  DentalDart Well-Known Member

                  Messages:
                  2,388
                  Likes Received:
                  1488
                  Joined:
                  Jul 5, 2019
                  Location:
                  Las Vegas
                  Local Time:
                  3:40 AM
                  Yea I can find it on craigslist for about 25 bucks a can.
                   
                • DentalDart

                  DentalDart Well-Known Member

                  Messages:
                  2,388
                  Likes Received:
                  1488
                  Joined:
                  Jul 5, 2019
                  Location:
                  Las Vegas
                  Local Time:
                  3:40 AM
                  Well I didnt drain anything out of my system originally because there wasnt anything in there.
                   
                • Phreakish

                  Phreakish Well-Known Member

                  Messages:
                  707
                  Likes Received:
                  353
                  Joined:
                  May 28, 2015
                  Location:
                  N. Idaho
                  Local Time:
                  3:40 AM
                  I've tried diy AC several times. I've gotten things to work, and then they fail again in short order.

                  Take it to a pro. Without any experience, it's very tough to know exactly what you're doing and whether it will work. In Vegas I'd look for a mobile guy who likes old cars..
                   
                  • Like Like x 1
                  • Agree Agree x 1
                  • toolmanmike

                    toolmanmike FABO MODERATOR Staff Member FABO Gold Member

                    Messages:
                    48,647
                    Likes Received:
                    33317
                    Joined:
                    Jan 18, 2006
                    Location:
                    Iowa
                    Local Time:
                    5:40 AM
                    You obviously have a leak or it wouldn't be empty. Unless you have a gauge set, a evacuation pump, and the correct oil and refrigerant you would be best to find a professional. And that's at a minimum. It takes special tools to diagnose and repair leaks.
                     
                    • Like Like x 1
                    • Agree Agree x 1
                    • Dana67Dart

                      Dana67Dart Like a fine wine, only getting better with age! FABO Gold Member

                      Messages:
                      4,128
                      Likes Received:
                      2497
                      Joined:
                      Jul 16, 2017
                      Location:
                      Northern Colorado
                      Local Time:
                      4:40 AM
                      In the heater box. Well in your case the heat/ac box.

                      Also do you have an external valve to shut the water flow to the heater core?, Not sure if that was stock in 68 or 69.
                       
                      • Thanks! Thanks! x 1
                      • Agree Agree x 1
                      • DentalDart

                        DentalDart Well-Known Member

                        Messages:
                        2,388
                        Likes Received:
                        1488
                        Joined:
                        Jul 5, 2019
                        Location:
                        Las Vegas
                        Local Time:
                        3:40 AM
                        It's not empty right now I dont think, I can press this and stuff comes out now.

                        It was empty. I dont think the PO ever charged it after swapping this engine into the car.

                        20200321_120627.jpg
                         
                      • MoparMike1974

                        MoparMike1974 FABO Gold Member FABO Gold Member

                        Messages:
                        2,201
                        Likes Received:
                        1521
                        Joined:
                        Jun 16, 2017
                        Location:
                        Maryland
                        Local Time:
                        6:40 AM
                        R12 is not illegal, however I believe it is out of production. You can still buy it but its expensive and you have to have the proper license to purchase.
                        I recently had to get a license just to buy a 30lb R134 so the laws are steadily changing.
                        Yes you must replace the dryer when converting from 12 to 134. The proper thing to do is replace it any time the system is opened. Also, R12 and R134 dryers use different dessicants in them. Pag oil and Ester oils should not be mixed so the system needs to be flushed.
                        Not much room for error when servicing and AC system. Sounds like you need to hire someone.
                         
                        • Agree Agree x 2
                        • MOPAROFFICIAL

                          MOPAROFFICIAL FABO Gold Member FABO Gold Member

                          Messages:
                          5,480
                          Likes Received:
                          4459
                          Joined:
                          Jun 1, 2016
                          Location:
                          Beach
                          Local Time:
                          3:40 AM
                          R12 is only illegal to sell.
                           
                        1. This site uses cookies to help personalize content, tailor your experience and to keep you logged in if you register.
                          By continuing to use this site, you are consenting to our use of cookies.