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Thread: Fixed my a/c!

  1. #1

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    Fixed my a/c!

    So I fixed my a/c today. I've been going between 2 threads about it so I'm going to make this as a how to thread for anyone having a/c issues. I have a feeling it'll answer alot of guy's problems. Mainly my point goes out to mitsupimpsled. I think this is your problem. Here goes

    What's wrong with your a/c? Not working? intermittent issues? Have a good refrigerant charge? This is mostly for electrical. First thing you wana do is drop the glove box out. THere's 2 tabs on the sides and it'll fall straight down. Infront of you is your Cooling unit, basically evaporator + wiring harness. At the bottom of this box is the Climate control unit. What you wana do is wiggle the connector and harness vigorously. Not weakly. If this causes your problem to come or go then you experienced what I did. First thing you wana do is pull it down, 2 phillips screws on the bottom and it comes down, pull it through the glove box opening for easier access. Is the connector difficult to remove? Does it have to be forced in? Then that's part of your problem. The socket has swollen and so have the terminals. What you need to do now is go on ebay and buy a radio connector. Theyre cheap and theyre the same connector! Here's an example.

    http://www.ebay.com/itm/Factory-Radi...bd8775&vxp=mtr

    Only problem with this is there's one empty terminal. Easy fix the kit comes with a smaller connector. Use a small flathead screwdriver and compress the tab inside and slide one of those pins out and pop it into the bigger connector.
    Now what you wana do is strip the harness back about 4" up to the pigtail for the evaporator temp connector exposing the wires. Then trace them all back to the connector and cut and solder one at a time. Once it's all done and cleaned up this new one should fit into your controller quite nicely and smoothly. This should fix your problem if it's not too major. If it is, Next is the major fix

    Major fix. Remove the black cover from the unit, 2 screws on the bottom, small flathead and pop it off. Now if the problem still exists by shaking the connector socket itself then keep going. notice this picture: Look closely at the 4 pins to the right of the screw hole.


    If you remove the screw (that was missing in my pic since I took mine out) pull and push the socket you'll notice these pins move in and out. The solder joints are broken. What you'll need is a fine tipped soldering gun, solder and a stable hand. Hold the gun parallel to the socket touching it just enough to warm it slightly. Touch it with some solder and it should drop onto the pins and melt perfectly. After this is performed the unit should function perfectly unless something internally like a diode or resistor has failed. Unless you're really good with radio shack and stuff like this you're gona need to hit up mitsubishi and control units are still available. Just take in your old unit with the p/n. Theyre around $100.

  2. #2



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    Congrats! Since when do we have to be PC board techs now? That is not in the Mitsubishi training course 101. Got a parts list for installing AC from bone stock non AC truck? I'd like to try it since all the trucks in Junkyard have AC's

  3. #3

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    Before mentioning parts I'll mention tools. You don't want to damage anything since nothing is available anymore. I had line wrenches but got lucky up front with the bigger lines since biggest i had was 13/16" and I used adjustable wrenches on most of it but I'm not in a salt state and I didn't have anything 24-27mm in wrenches. I recommend a good set of line wrenches since most of the lines require 2 wrenches to break them loose to prevent twisting and cracking the lines.
    Other than that a good screwdriver and some 12, 10 and 14mm sockets with a 19mm wrench for the temp sensor is all you'll really need. I also recommend some ziplock bags for storing hardware and brackets since very little of your hardware is on the truck already.


    Parts needed:

    Compressor, condensor, (with dryer brackets only. You'll end up getting a new dryer period. You'll have to retrofit unless you manage to find a 93+ truck) evaporator (cooling unit) + bolts + body grommets
    Harness from driver side fender (a blue connector) it goes to the temp sensor, to compressor, houses a relay and fuse then runs under bumper and grille and around to the passenger side where it connects to another sensor then runs into a plug that goes into the firewall. It goes into the truck with the cooling unit and connects to the stock harness inside. You can leave the harness on the cooling unit and slide it out. Don't forget it's a chrysler product so the cooling unit has 2 bolts inside and one outside the firewall. You'll also need the 2 big sleeves around the cooling unit and it's drain tube.
    A/c button (removable from control head by 1 screw. A special screw. You'll need it.)
    Lines from compressor to condensor and condensor into truck
    Bracket for compressor and this bracket also holds the belt tensioner
    Most important 2 things you'll need:
    1: the temp sensor from the thermostat housing. If you dont have a/c yours will have a 10mm allen plug in it.
    2: the fan shroud if yours isn't the large metal one.

    My donor didn't have a shroud and my truck had the wrong radiator which I took from donor so I don't have a shroud. On hot days at idle my a/c will fade out since high side pressure will approach 300psi until you spray the condensor with a hose then it'll drop to the 175-200 threshold. I may end up converting to an electric fan. If anyone's done this chime in.

    Removing the old from donor.
    Only advice I really need to give here is to drop the glove box out with 2 screws and you can get the cooling unit out. I removed the dash to learn the hard way. The plugs are accessible from that hole and the unit will come out. This is the way it was designed to be put in at the dealerships when they were new. Also the a/c plug will require you to move the control head back some to make room, not remove. However putting the button in yours may shift the cables around a bit so make sure yours don't slip out of the retainers. Make sure the sliders all work afterwards.

    My recommended procedures.
    I changed all the o-rings by buying a retrofit kit from NAPA auto parts. It had alot of different green a/c o-rings various sizes. This system only uses about 3 sizes anyway. A similar kit can be found from harbor freight. Just make sure it's green o-rings
    I poured the compressor oil out.
    I replaced the dryer.
    I replaced the belt.

    Install:
    Reverse order of removal.
    put the compressor in first with hoses. Then cooling unit and electrics and plugs. The inside of the truck there's a piece of insulation that can be removed to access the plugs in the firewall. No cutting or anything required. Before installing the box, start the drain tube in it's grommet. It's a tight fit once the box is in. HIGHLY recommend to grease the crap out of the drain tube and grommet or you'll get the drain tube half way through and it'll pop the grommet out never to be installed again without removing the tube which requires you to remove the unit. Don't skimp on the grease. Then put in all wiring, plug it up then proceed outside to install all lines.
    Leave them all loose just get the joints started since theyre metal lines. Fitment will be tight so they need to be loose. Once lines from cooling unit are in you can put in condensor and the big low side line that runs infront of it. The bumper won't have to be removed but the middle radiator support and latch will. (don't remove the cable just disconnect the clip by the latch and lay it to the side) So I recommend after you're done hook up the latch, close the hood, line up the fenders to the hood and tighten up the bolts on the latch BEFORE re-installing grille. Just some advice.

    Once your system is together it's time to charge it. Assuming you followed my directions and drained the oil in the compressor.

    You'll need to charge to around 1.5 lbs of refrigerant and 6 oz of oil. This is R-134 specs. (Due to my electrical issues I haven't had the chance to efficiently check my pressures to say this is the perfect charge amount but it's blowing about 45-50 degrees on an average day but it seems weak since it was only 75 yesterday. I'll test it on a warm day. I have a feeling the pressure is low and it may need another .5 lb. I'll update as I learn new changes.)

    The compressor may rattle at first since the donor most likely has been sitting for awhile. This should quiet down as the oil runs through the system. If you're working now then you're good. If not make sure you didn't forget to plug anything in. If still no good refer to post #1.
    Last edited by recian; 05-26-2013 at 07:45 AM.

  4. #4

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    Good job buddy. Mine idle problem still has not went away on its own but I do plan on working on that little black box soon. I believe I pulled the harness out from under the dash on my donor truck so I believe I actually have another connector. Other than that I am still lost on the idle problem. Going to check timing and all that next and try a new EGR. Glad you got yours fixed and working correct. I don't see where I missed any step in your writup there from my install. I couldn't ask for the a/c to work any better than it does honestly, it's just the truck don't want to idle correct. Anywho...

  5. #5

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    I still wouldn't rule out the controller on your truck since the idle up signal is sent from the control unit. It's possible it's got a bad resistor for the idle signal and it'll send signal, heat up and open then as it cools the circuit will close and it'll idle up again. Mine would do the same idle up issue if I wiggled the harness but the pin for the compressor relay was also loose.

  6. #6

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    Ha figures today I was trying to get my doors in the heater box working. I finally got them decent. I can feel air on my face now but it's still not very strong. I can see in the box and the doors are still covered in foam. During the process I heard a loud pop sound then it sounded like a/c leaking... and it was. I found my firewall painted green. The valve on the back of the compressor let the refrigerant out. I hope it's just due to my high side issue at idle since it was idling for awhile. I'll find out tomorrow if the valve is still leaking but it let out all my refrigerant so I can't even get the compressor to come on now. Maybe I'll recharge it with esther oil if I can find some to be safe.

  7. #7

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    Same problem on my 95'. I was finding 12v in and I believe it was 7v out. It's been a while so the values might be wrong. I ended up for now just running a jumper wire between the terminals (removed black box) so it doesn't cycle but it works with a/c blower switch or a/c button. It idles up when switched on just like it should. Everything checked out, thermistor etc. but I'll look into that black box

  8. #8

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    Here's a picture of my black box...sorry couldn't edit my other post.
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  9. #9



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    How high is the pressure on the high side? It might be that things were working correctly just the TXV thermal expansion valve) or orifice tube is plugged up and needing to be replaced. If it made pressure to pop the line then it has a restriction in the system. The thing that sucks is you need to pull a vacuum on the system again.
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  10. #10

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    Looks like your unit may have the same issue. Remove that screw and push/pull on the connector and see if the pins by that screw move.

    Yeah my high side was reaching 300 at idle until I sprayed water on the condensor so my problem is lack of airflow. This was after a minute or 2 of idling. I wonder how high it got after 15 minutes of idling.

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