ABF ECU Pin 39 (Mk2, AC)

Discussion in 'Electrical' started by GG., Apr 15, 2019.

  1. GG.

    GG. Forum Member

    Joined:
    Dec 2, 2013
    Likes Received:
    47
    Location:
    Latvia, Riga
    Hi Folks,

    So I put an ABF (97' GTI with Climatronic) in my 91 Mk2. I removed all the unnecessary wires from the mk3 engine bay loom along with the fan control relay box. I am running a stock Mk2 fan.

    Along with the engine conversion, I am installing an AC system that came from a 91 Mk2 GTI 16v. I am using the mk3 AC compressor, everything else (pipes, switches, relays, wiring) is mk2 parts.

    So, when cleaning up the ABF wiring loom, I left one wire dangling ECU Pin 39. I forgot where it was connected to originally in the mk3 application (it was a long time ago). Is that a signal wire for the ECU when the AC compressor and fan engages, so that the ECU can compensate the load with altering the idle speed? If it is so, where should I tap it in to?
     
  2. GG.

    GG. Forum Member

    Joined:
    Dec 2, 2013
    Likes Received:
    47
    Location:
    Latvia, Riga
    Hmmm, do I just pin it in
    N/05 A/C Switch A/C Relay A/C "On" Switch [:[]
     
  3. rubjonny

    rubjonny Administrator Staff Member Admin

    Joined:
    Oct 31, 2003
    Likes Received:
    3,298
    Location:
    Bracknell
  4. GG.

    GG. Forum Member

    Joined:
    Dec 2, 2013
    Likes Received:
    47
    Location:
    Latvia, Riga
    So when the low pressure switch turns on the AC compressor, or high pressure switch turns off the compressor and fan, it signals the ECU with +12v. Since I'm not returning to the mk3 fan control unit, the question is what is the equivalent in a mk2 setup. I have the CE2 plug N in the fusebox.

    It seems that the N/05 AC Switch is not the one.

    N/04 A/C compressor (via thermostat and pressure switches) A/C Relay Compressor Output Green/Yellow

    I think this would be the mk2 equivalent? If that's the one, I could just tap that ecu pin 39 wire to this terminal in fusebox? Sorry, I'm a bit of a dum dum when it comes to all things electrical. And the system is not yet filled up, so I can't really test it now. I wanted to sort out all the wiring before filling it up.

    Thanks Rubjonny!
     
  5. rubjonny

    rubjonny Administrator Staff Member Admin

    Joined:
    Oct 31, 2003
    Likes Received:
    3,298
    Location:
    Bracknell
    sorry I miss-read! Thought you said you were using the MK3 wiring.

    For MK2 wiring you would put it on the green wire spade hanging about near the fusebox, its on the N/4 wire AC relay trigger for the compressor, bottom right:
    Clipboard01.png
     
    GG. likes this.
  6. rubjonny

    rubjonny Administrator Staff Member Admin

    Joined:
    Oct 31, 2003
    Likes Received:
    3,298
    Location:
    Bracknell
    or if you'd rather have a VW diagram than a Mitchell ;)
    aircon-1.gif aircon-2.gif
     
  7. GG.

    GG. Forum Member

    Joined:
    Dec 2, 2013
    Likes Received:
    47
    Location:
    Latvia, Riga
    You are a legend Rubjonny :thumbup::clap: Many thanks!
     

Share This Page

  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.
    Dismiss Notice