1UZ Variable A/C Compressor Wiring

Discussion in 'Wiring' started by Frank Clark, Sep 16, 2018.

  1. Frank Clark

    Frank Clark Member

    Joined:
    Apr 28, 2017
    Messages:
    46
    Likes Received:
    4
    Trophy Points:
    8
    Gender:
    Male
    Location:
    Fairview, TX
    I've decided to add A/C to my race car (OK, call me a wimp). Have a Vintage Air unit. Mounting of the Sanden compressor would be problematic. So I am planning on using the Toyota compressor. This is on a VVTi 1UZ.

    The A/C compressor has electronically variable vanes (as well as a clutch).

    Any ideas on how I need to apply signal/power to the plug to force the compressor to max output?
     
  2. gloverman

    gloverman Well-Known Member

    Joined:
    Oct 15, 2004
    Messages:
    2,697
    Likes Received:
    55
    Trophy Points:
    48
    Occupation:
    mechanic
    Location:
    Hamilton. New Zealand
    I have done lots of engine swaps with a/c and use an early pump of gen1 or gen2 and wire clutch only. Easy as.
     
  3. Frank Clark

    Frank Clark Member

    Joined:
    Apr 28, 2017
    Messages:
    46
    Likes Received:
    4
    Trophy Points:
    8
    Gender:
    Male
    Location:
    Fairview, TX
    Does the early pump bolt on the same mount? I'm in the US and have checked early model LS400, SC400 and the Toyota Tundra (2UZ). All the compressors look like they have the solenoid for electronic variable vanes (in addition to the clutch).

    Can you point me to a specific compressor?
     
  4. gloverman

    gloverman Well-Known Member

    Joined:
    Oct 15, 2004
    Messages:
    2,697
    Likes Received:
    55
    Trophy Points:
    48
    Occupation:
    mechanic
    Location:
    Hamilton. New Zealand
    As I'm in Nz we we mostly JDM stuff. Im doing a 3uz atm with the right pump so will attempt to shrink the photo to upload here. It was of a UZZ30 soarer.
     
  5. George_R

    George_R Member

    Joined:
    Sep 13, 2010
    Messages:
    891
    Likes Received:
    16
    Trophy Points:
    18
    Gender:
    Male
    Occupation:
    DSP engineer
    Location:
    Russia, Moscow
    Home Page:
    Stock or aftermarket ecu? (idle up options depend on this)
    As for flow control valve, I use aftermarket pwm controller available in local radio hobby store. It's reported to have fragile coil winding that overheats and burns if you feed it with constant 12v
     
  6. Frank Clark

    Frank Clark Member

    Joined:
    Apr 28, 2017
    Messages:
    46
    Likes Received:
    4
    Trophy Points:
    8
    Gender:
    Male
    Location:
    Fairview, TX
    Aftermarket with IAC and manual TB.

    I have spare PWM outputs. I think they are rated at 2a. Also have spare inputs, so if I need to monitor temp and adjust PWM up/down that should be straight forward.
     
  7. George_R

    George_R Member

    Joined:
    Sep 13, 2010
    Messages:
    891
    Likes Received:
    16
    Trophy Points:
    18
    Gender:
    Male
    Occupation:
    DSP engineer
    Location:
    Russia, Moscow
    Home Page:
    Constant PWM is ok from my experience
    So you use one as on/off for the clutch relay, another one for constant pwm when a/c is on and that's pretty much it
     
  8. Frank Clark

    Frank Clark Member

    Joined:
    Apr 28, 2017
    Messages:
    46
    Likes Received:
    4
    Trophy Points:
    8
    Gender:
    Male
    Location:
    Fairview, TX
    The car has no insulation, door seals or side windows so max all the time would be great. I wonder what the max equates to and how to figure out which pins are which.
     
  9. George_R

    George_R Member

    Joined:
    Sep 13, 2010
    Messages:
    891
    Likes Received:
    16
    Trophy Points:
    18
    Gender:
    Male
    Occupation:
    DSP engineer
    Location:
    Russia, Moscow
    Home Page:
    By testing for resistance and knowing what you have there (lock sensor, mag.clutch, pressure control valve)
    Safe pwm value is 50%
     
  10. Mat Grant

    Mat Grant Member

    Joined:
    Jul 11, 2008
    Messages:
    139
    Likes Received:
    2
    Trophy Points:
    18
    Occupation:
    project manager
    Location:
    southern UK
    Hi, I've got an early Denso AC compressor on a 1992 1UZ with the 40/40/40 pin ECU. I have just wired 12v to the mag clutch off a relay from the AC button / climate control in the car. But I have not sent any connection from this to the ECU, the idle does drop significantly when the AC is engaged, please can anyone tell me what pin I should send the AC 12v to tell the ECU the AC is on?

    Sorry for the thread hijack :)

    Cheers, Mat.
     
  11. Frank Clark

    Frank Clark Member

    Joined:
    Apr 28, 2017
    Messages:
    46
    Likes Received:
    4
    Trophy Points:
    8
    Gender:
    Male
    Location:
    Fairview, TX
    The ECU actually grounds the PWM signal, so it seems the easy solution is to connect the clutch+ to the PWM+, and PWM- to the ECU. Then ECU can always provide 50% signal and turning the clutch on/off will actually power the clutch and the control valve.

    Sound reasonable?
     
  12. Frank Clark

    Frank Clark Member

    Joined:
    Apr 28, 2017
    Messages:
    46
    Likes Received:
    4
    Trophy Points:
    8
    Gender:
    Male
    Location:
    Fairview, TX
  13. Mat Grant

    Mat Grant Member

    Joined:
    Jul 11, 2008
    Messages:
    139
    Likes Received:
    2
    Trophy Points:
    18
    Occupation:
    project manager
    Location:
    southern UK
    Hi Frank,

    Thanks for putting up the link, I have that diagram, just not clear on which is the input to the ECU.

    Mat.
     
  14. gloverman

    gloverman Well-Known Member

    Joined:
    Oct 15, 2004
    Messages:
    2,697
    Likes Received:
    55
    Trophy Points:
    48
    Occupation:
    mechanic
    Location:
    Hamilton. New Zealand
    I had my lastest gased up this week . Its a vvti running an early soarer (sc400) non-vvti pump. Only the clutch connected and its working well. I couldnt find any numbers on the pump sorry.
     

Share This Page