Results 1 to 3 of 3

Thread: ac compressor clutch - quick question

  1. #1
    94 3500gt vr2? verified Feedback Score 9 (100%) n2nsanity's Avatar
    Join Date
    Sep 2010
    Owner Since

    Blog Entries
    Thanked 29 Times in 17 Posts

    ac compressor clutch - quick question

    My question is, could poor connections on the 2 sensors on the compressor cause the clutch not to engage?

    Long Explanation:
    I'm having issues with my clutch not engaging.
    I put it in my current build and have never used it in anything else.
    I flushed the whole system and added plenty of r134
    Ac light comes on, not flashing
    Condensor fans come on.
    Changed out the entire ac relay, same results.
    Tested clutch wire and compressor directly to battery, hear the click, it definitely works.

    Then I remembered it's a reman'd compressor off ebay and it was heavily painted, including the 2 sensor's connectors
    I hit them with the wire brush to get the paint off and pushed connectors back on
    Can poor connections on these 2 sensors cause the clutch to not engage?
    I have to wait until tomorrow morning to find out if it worked for other unrelated reasons.

  2. #2
    Never finishes any verified
    Feedback Score 8 (100%) DrGonzo's Avatar
    Join Date
    Sep 2010
    Owner Since

    Wake Forest, NC
    Thanked 197 Times in 140 Posts
    If you hotwire the clutch and it kicks that I doubt it is the connections. The A/C compressor has two failsafe sensors that usually cause the issues. The first is a pressure switch, If the system is over charged or when running it builds to much pressure, it will kick the clutch off. this prevents the compressor from blowing the pressure release valve "which makes the compressor useless"

    The second is an RPM sensor. It tracks the RPM's of the compressor and basically matches them to the engine RPM's. If they are out of range it will shut off the compressor as the system thinks the compressor is locking up and the belt is slipping "Prevents the belt from breaking". The control unit for the RPM switch is the little black box mounted to the top side of the pass kick panel. I disabled it by clipping the tach signal line going into the box "Believe it was a white wire". Removing the tach signal basically ignores the speed sensor on the compressor as it computer will always see the compressor RPM as higher that the engine RPM's "Which it should under normal conditions". The speed sensor is usually the first thing to go out on the compressor and they are not replaceable. So you can either clip the RPM wire or buy a new compressor. I went the cheaper of the two and it worked great.

    I suggest first clipping the tach signal wire and see if that resolves the problem. You can bypass the pressure switch but it is not recommended as a permanent fix. I tired it once and after a couple weeks on a rally hot day the pressure release valve blew on the compressor making an absolute mess of the engine and rendering a good compressor worthless!

    Check it out on Youtube!!

    93 Stealth TT - The Stealth Project

    Renegade Tech Works ECS Controller on Intrax Springs
    Chrome ECU
    Hybrid 13g's
    EVO 560cc Injectors
    Spec Stage 3 clutch
    Ninja Performance Output shaft & Input spool
    Ninja Performance Solid Tensioner & Gates racing T-Belt
    CX Racing Dual Core FMIC
    Megan SS Exhaust
    Fidanza Cam Gears and Clear Covers
    3rd Gen Lifters
    K&N FIPK
    Maximal High flow converter
    Walbro FP & FuelLab FPR
    Maximal and Seattle Solid Mounts
    All -6an Lines
    Custom -6AN coolant neck lines
    AWS/ABS/Cruise Delete
    MP Rear Control Arms
    SS Brake Lines
    99 Front Conversion
    2nd gen Rear Bumper
    99 Combat Wing
    Complete interior LED Swap
    Skillard Fuel channel
    Oohnoo FPR Bracket
    More to Come......

  3. #3
    94 3500gt vr2? verified Feedback Score 9 (100%) n2nsanity's Avatar
    Join Date
    Sep 2010
    Owner Since

    Blog Entries
    Thanked 29 Times in 17 Posts
    waiting on my rtv to fully cure, 10 hours to go
    then i can add oil back in the engine
    start her up and hope and pray the leak is gone
    then i'll test the ac again

    if it's not working, i'll try that wire, gonna go look for it now in case
    also bringing my other compressor, just in case

    my car's gonna weigh like 5k pounds with all the extra bs i'm bringing lol


Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
The 3000GT/Stealth/GTO Web History Project
3000GT / Stealth International WWWboard Archive
Jim's (RED3KGT) Reststop
3000GT/Stealth/GTO Information and Resources
Team 3S
3000GT / Stealth / GTO Information
3000GT/Stealth/GTO Clubs and Groups
Michigan 3S
MInnesota 3S
Wisconsin 3S
Iowa, Nebraska, Kansas 3S
North California 3000GT/Stealth
United Society of 3S Owners
3000GT/Stealth/GTO Forums
3000GT/Stealth International
3000GT/Stealth/GTO Event Pages
3S National Gathering
East Coast Gathering
Upper Mid-West Gathering
Blue Ridge Gathering