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Shifty_P's avatar
Shifty_P
Explorer
Jul 01, 2017

Dash A/C issue

I own a 1993 Cobra Monterrey 30. I purchased it a little more than a month ago. For the first couple weeks. There appeared to be no issues with the Dash A/C. While on a trip last week, I noticed the A/C was not working. Initial troubleshooting determined that the clutch on the compressor was not engaging. Using a volt meter. I drtetermined there was no current going to the clutch solenoid to engage it. As fter checking all fuses, and relays I believed it was the low pressure sensor causing the compressor not to turn on. I bypassed the shutoff, and engaged the clutch using an external 12v source. With the clutch engaged, I was still unable to get the system to take any additional refrigerant. While the compressor was running, the air coming through the vents was also the same temperature as the outside air. I'm not sure what I should look at next. Any help would be appreciated.
Class A
  • Cobra21's avatar
    Cobra21
    Explorer
    Jul 01, 2017
    When you try charging the system while it is running (jumping the low pressure switch) Put your can of R34A in a pail of hot water, from a house faucet. Open the low side gage fitting and it will go into the system (refrigerant can up) Once you have enough refrigerant it will run on its own without the jumper.
    Brian
  • Shifty_P's avatar
    Shifty_P
    Explorer
    Jul 01, 2017
    Bikeboy57 wrote:
    What are your gauge readings while jumping the clutch?


    Which gauge are you referring to? If you're referring to the gauge on the r134 dispenser hose, it reads nothing when the trigger is pulled to dispense the refrigerant. As soon as I release the trigger, it jumps up to 150psi. It's the same result as before I realized the clutch was not engaging, and the compressor wasn't running.
  • wa8yxm's avatar
    wa8yxm
    Explorer III
    Jul 01, 2017
    For AC work there is something called a Manifold Gage Set, Two gauges, Two valves and 3 hoses

    Two of the hoses connect to the HIGH and LOW pressure ports on your A/C system..THe fittings will NOT connect to the wrong hose.

    The 3rd hose to a tank of Refrigerant, and then the two valves decide if you pump high pressure refrigerant into the tank or if the tank feeds into the low pressure side.

    These are the gauges.

    Link to Amazon catalog page

    You can also get a single (Low side) gauge it is much less expensive and nearly as informative as the full set in most cases (But not all)
  • jyrostng's avatar
    jyrostng
    Explorer
    Jul 01, 2017
    If it's all the way empty, it will show zero until it has some pressure in the system. it's possible it had a leak and the dealer topped it off and it lasted a month till it all ran out. Evaporator coils are bad about leaking.
  • Shifty_P's avatar
    Shifty_P
    Explorer
    Jul 02, 2017
    How long should it take the can to empty into the system? It seemed like absolutely nothing was coming out of the can.
  • jyrostng's avatar
    jyrostng
    Explorer
    Jul 02, 2017
    The can will get cold if the refrigerant is going out of the can. Make sure you have the fitting on all the way. Push down hard with the sleeve on the hose fitting in the up position and release the sleeve.
  • JohnG3's avatar
    JohnG3
    Explorer II
    Jul 03, 2017
    You should find the leak and have it fixed before you spend too much time wasting effort on something that will not fix itself without finding what's causing the leak. There are some refrigerants that have a dye in them to help locate the leak. If the leak is at the compressor seal (most likely if the rig was left sitting with no use for a significant time), then the easiest fix is to replace the compressor with new or rebuilt.

    If not the compressor keep looking for the dye then go from there.
  • falconbrother's avatar
    falconbrother
    Explorer II
    Jul 03, 2017
    Does your service line have a gauge? If not find one. The last one I bought was at Ollies for like, ten bucks. I have a full manifold gauge set but, just find it quicker and easier to use the cheap low side hose and a can of refrigerant. If the system is out you have a pretty serious leak and the system is contaminated. You need to get the leak fixed and have it drawn down before adding refrigerant. If it still has some pressure you can charge it but, if it were mine I would add some stop leak. Don't even bother with the cheap stuff. It won't work. Get the good stuff, like $30.00 a can. Then service it up to a proper pressure, obviously with the compressor running. I put that stop leak in an old Volvo years ago and it worked till I sold it and never leaked down.
  • Shifty_P's avatar
    Shifty_P
    Explorer
    Jul 03, 2017
    After trying again with a different dispenser, it still will not recharge. After trying to recharge it for approximately 10 minutes, no refrigerant is leaving the can. There also appears to be no pressure at all in the system.

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