OEM management wiring: 1.8T => Mk2 harness install FAQ

Discussion in '1.8 & 1.8T' started by 20v_jimmy, Dec 29, 2009.

  1. rubjonny

    rubjonny Administrator Staff Member Admin

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    hmm. best speak to loom builder then...
     
  2. Todd Motto Forum Member

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    That’s my problem though, I bought the project car from a guy who has no info apart from that he bought it “from a forum for an AUM with the MAP sensor relocated”. That’s literally all the info I have. Am I doomed? Lol.
     
  3. rubjonny

    rubjonny Administrator Staff Member Admin

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    ok so first thing get a multimeter and probe see if any of them have voltage. IIRC the cluster will put 5v on the 3 oil sender wires but I cant get to my car to double check.or alternatively you could get a multimeter and try a continuity test on those 3 wires back to the fusebox pins

    Another thing you could try is get yourself a 5a fuse tap it inline with each wire one at a time, then earth with ignition on see if the fuse blows. hopefully, they are your 2 oil switch wires and mfa oil temp. earthing the low switch will cause light on dash to flash ignition on, oil temp will make oil temp go to full and high switch will stop the light + buzzer when engine is revved.

    ideally you would strip the loom back to fully investigate but its a bit of a hassle...
     
  4. Todd Motto Forum Member

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    Yeah that’d be one massive task to strip it all back! The good news is that the wire is in the correct position to be used as an oil pressure sensor as all other wiring there is done. What do you think?
     
  5. rubjonny

    rubjonny Administrator Staff Member Admin

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    it would be my guess for sure
     
  6. Willsie23 New Member

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    Hi all - just read this end to end a few times! What a great read and collection of knowledge!
    A friend and I are in the process of dropping a 1.8t BAM lump into his autograss class 7. I've taken on the task of sorting the wiring for him so this is invaluable!

    The question coming from me is, with no 'other' loom for us to connect to as we don't have a car needing lights/internal electrics etc can we effectively ditch the vast majority of the connectors that go back to the car loom?

    My thinking here being - we'll have a master power switch that will supply the ECU, fuel pump switch to power the hi-lift pump and a starter button, so the need for some of the fuel pump relay etc is overkill.

    Just want to get some reassurance I'm not over simplifying things!
     
  7. rubjonny

    rubjonny Administrator Staff Member Admin

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    yeah theres not much you need to get it running really, powers and earths on t6 and t10/14a job done. i would recommend you at least wire a fuel relay triggered by the ecu, that way if you crash it'll cut out right away and not wait till someone comes along and cuts the master switch.

    you can easily re-purpose the SAI 100 relay for this, cut the brown/grey earth trigger for the relay from to the ecu and splice the ecu purple/white fuel relay trigger wire from T6/2 to it instead. run the fat red to battery/main live. white/red chunky output that used to go to SAI pump tap to all your ecu loom power feeds on T6/5 and also pin 6 if in use on your loom, plus & t14a 5 & 6 with suitable fuses (can use the empty fuse sockets in the relay box even) finally cut the blue/yellow to relay and run that to an ignition live rather than fuel pump live

    428 relay is your main ecu/coil power just leave that as is, the main input feed to it comes from T6 plug pin 4, put that to a good live with inline fuse job done. T6/1 black needs an ignition live, tap that to same feed as the SAI 100 relay ignition I mention above and that'll power it all up

    be a good idea to wire T10/1 diagnostics wire to a vagcom port, and T10a/9 you probably want so you have a rev counter but thats up to you. see my thread as well:
    https://clubgti.com/forums/index.ph...install-faq-now-with-added-dieselness.267196/
     
    Willsie23 likes this.

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