Lincoln AC Went Out - Help!

Discussion in 'Off-topic' started by Phil1979, May 19, 2017.

  1. Phil1979

    Phil1979 Member Georgia Carry

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    Drove to the store two days ago, AC blowing cold. Got back in car (2007 Town Car), blowing hot air.

    Compressor will not come on at all now.

    Replaced AC Relay and low pressure switches. 15amp feed fuse is good.

    When first turning on the AC it sounds like the compressor kicks on, but it's really just the relay (or something) trying to get it going.

    Maybe it is the compressor, and the clutch is just locked.

    Can I bang on it with a hammer? Or do I need to replace the clutch?
     
  2. Smilodon

    Smilodon Active Member

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    Banging with a hammer will not fix it.
     

  3. Smilodon

    Smilodon Active Member

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    The clutch is not locked up. If it was, the compressor would run all of the time. The coil in the clutch could be weak or burned out, could be a bad connection going to the coil, could be low on refrigerant
     
  4. mountainpass

    mountainpass Under Scrutiny

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    Then a match it is
     
  5. Smilodon

    Smilodon Active Member

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  6. Phil1979

    Phil1979 Member Georgia Carry

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    How do I check that?


     
  7. rmodel65

    rmodel65 Yukon Cornelius

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    Does the compressor come on when you just the low pressure switch with a paperclip?
     
  8. Smilodon

    Smilodon Active Member

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    With a test light or volt meter. Unplug the clutch and test for power and ground.
     
  9. Smilodon

    Smilodon Active Member

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    You can do that too, it will test the circuit.
     
  10. Marine6212

    Marine6212 Active Member

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    check out batauto.com it's a webforum for gear heads by master mechanics. they have the tech data and wiring diagrams that they can and will post to help you!
     
  11. Phil1979

    Phil1979 Member Georgia Carry

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    Mystery solved, thanks everyone!

    I jumped the low pressure plug with a wire, and boom, the compressor came to life!

    I had some leftover coolant (a little) from way back, so I put that in, and with everything plugged back in, the compressor cycled on and off.

    Will need to pick up more juice later.

    But this is odd. One minute cooling fine, next minute nothing at all but hot air. Do I have a leak somewhere? My AC was just about completely rebuilt with all new parts just over a year ago.
     
  12. Smilodon

    Smilodon Active Member

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    Yeah, you have a leak somewhere. Check the service ports sometimes the valves leak. If a valve is leaking you may hear a hiss when you remove the cap, also look for oil residue. Some valves have a little rubber tit that can break off and hold the valve open.
     
  13. AtlPhilip

    AtlPhilip Proud GCO member.

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    If no leak, the clutch pads could be worn out. The gap gets too wide for the magnets to engage.

    Fords use a shim. Remove it, the gap shrinks (0.032 IIRC), and you gain a few more years life. When that stops working, it's clutch time.
     
  14. jsaund22

    jsaund22 Ninjaneering Computers

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    My wife had a van where the electromagnet actually went out. The part was $13, but I had to completely disassemble the entire front end of the car to get to it to replace it.

    But yes, sounds like you have a leak.
     
  15. Phil1979

    Phil1979 Member Georgia Carry

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    Yep, I do believe it's a leak. And probably in a line port. How much would it cost to get a line or lines replaced?
     
  16. Smilodon

    Smilodon Active Member

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    Not cheap, probably 2 to 3 hours of labor with a Evac an recharge, plus parts. Some valves are replaceable without replacing the whole line though and some are made to the dryer.
     
  17. Phil1979

    Phil1979 Member Georgia Carry

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    What should the pressures be on the low and high sides when the system is charged? I can't find specs on it. My google-fu is poor in this area.

    I plan to borrow a dual gauge and do this right. With a single gauge, it reported 30 lbs, but I think that's low. I could just have a slow leak and just didn't charge it enough.
     
  18. Phil1979

    Phil1979 Member Georgia Carry

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    Forgot to mention, there is some sort of green goo or oil inside the high-side port.

    Oh, and I need a tool to tighten down the shrader valves deep inside the ports, in case they are loose. I have no idea what that is called.
     
  19. rmodel65

    rmodel65 Yukon Cornelius

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    that green goo is probably your schrader valve leaking you can try tightening it with a valve stem tool. the green stuff is a mix of oil and uv dye. you can use a black light and see if you see any other places wet as well...
     
    Last edited: May 23, 2017
  20. Phil1979

    Phil1979 Member Georgia Carry

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    Thanks RM. I tried my shrader bike tool but it's too short. I'll see if the auto parts store has one that will work.

    Now, all I need to know is the specs. Hopefully, that was the source of the leak, and an easy fix!