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Thread: A/C cycles on and off

  1. #1

    Default A/C cycles on and off

    It seems the a/c compressor cycles on and off and never just stays on. When it turns on there is a very noticable loss of power.. Is this normal or should it stay on all the time when it's turned on.

  2. #2
    Join Date
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    Completely normal.
    I think the frequent cycling prevents the unit from literally freezing up. IOW, it should never stay on continuously.
    The A/C pulls down the idle speed, but it shouldn't affect power very much as there is a cut-out switch that disables the A/C under heavy acceleration.
    Joel

    '67 Lotus Elan S3 DHC (owned since 1970)
    '17 Ford Focus RS

  3. #3

    Default

    Thanks Joel, that makes total sense.

  4. #4

    Default

    What Joel said is true, the compressor won't run constantly even when everything is copacetic. OTOH, frequent cycling can also be a sign of insufficient freon. The pump kicks in and the low side pressure drops below the trinary switch low side pressure trip point, which causes the compressor to cut out. When the compressor cuts out, low side pressure rises about the low side trip point, causing the compressor clutch to engage again. Shampoo, rinse, repeat.

    If needed, it's very easy to top off the system yourself if you get one of the kits that includes a pressure gauge.

    Jeff

  5. #5
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    Rossion or Noble?

    There is a Rossion mod.
    Dino

    Sarthe Grey Rossion Q1 (Sold to a good home in Colorado)
    Wolf GB08 LMP3/CN Sports Prototype www.motorsports-sw.com www.wolfracingcars.com
    Red 2006 A4 (slow but good gas mileage)
    2012 Audi Q7 TDI (Awesome Highway & Tow Vehicle w/Torque and High MPG)

  6. #6

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    Noble, I'll re-charge the system and see if that makes a difference.

  7. #7
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    Dino Can you shoot me a link to the Rossion Mod? Thanks

  8. #8
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    I don't know if the mod was on here. Craig at Rossion can send it to you. I am sure I don't have the email any more.
    Dino

    Sarthe Grey Rossion Q1 (Sold to a good home in Colorado)
    Wolf GB08 LMP3/CN Sports Prototype www.motorsports-sw.com www.wolfracingcars.com
    Red 2006 A4 (slow but good gas mileage)
    2012 Audi Q7 TDI (Awesome Highway & Tow Vehicle w/Torque and High MPG)

  9. #9
    Join Date
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    On my Noble the compressor is engaged for 10 seconds and then cycles off for about 4 seconds then comes right back on...

  10. #10

    Default

    mine does about the same, I dont think it's normal though so for the moment I have it off.

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