OEM MK4 management wiring => Mk1/2/3 harness install FAQ (Now with added dieselness!)

Discussion in 'Engines' started by rubjonny, Nov 8, 2013.

  1. rubjonny

    rubjonny Administrator Staff Member Admin

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    you only need to add one relay for the ecu and coils, use the factory fuel relay for injectors etc Z/1 or N, G1/8 or E/14 spade etc.

    you only need the 4 pin coolant sensor in the side flange, the one in the plastic fitting in top coolant hose is for aircon and any others for other stuff you dont care about
     
  2. Sverre Lervik New Member

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    Hi
    Tach works with converter

    Oil pressur switch mk1. Is blue/black wire 1.8 bar or 0.3bar on mk1 CE1 fusebox? Some say its 1.8 and others say 0.3 Ande blue/black are D1!?
     
  3. rubjonny

    rubjonny Administrator Staff Member Admin

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  4. Ignas New Member

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    So if I'm correct spade N in CE1 is Glow Plug/Fuel Pump Relay Pin 3 (output before fuse), I will need just to add fuse.?
    And on old harnnes I found socket for relay but acording colors I can't figure out purpose of it.
    [​IMG]
     
  5. rubjonny

    rubjonny Administrator Staff Member Admin

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    yes N and Z/1 are on the output pin of the glowplug/fuel relay, but before the fuse. many mk2/3 injection engines use this for the injector power and/or engine electrics without a fuse so its your call on whether to fuse the feeds or not.

    as per my first post for any feeds which are more vulnerable to damage fuse, so n75 as its near exhaust, lambda as under the car, coilpacks as the wiring can crack plus failed coilpacks can put a massive load on the feed. things which are tucked up reasonably safe you can get away with such as injectors like Vw decided for mk2/3 injectors. no harm in adding fuses for everything, up to you. use VW fuse holders ideally so they clip neat to fusebox, or if you have the big mk4 relay box these have 3 or 5 spare fuse holders inside which you can use

    relay there is for coolant level warning system, needs a 42 or 43 relay. if left empty the dash will work as normal just without low level warning. you can wire later mk2/3/4 header tanks to it will still work fine :)
     
  6. cupracraig

    cupracraig Paid Member Paid Member

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    Hi John, an i run a couple of things past you as i've re-made my loom and just needed to check.

    The car fuel pump primes and i can crank the car over so thats fine. but i'm not hearing the AGU throttle body adjustment like it used to. So ive checked some voltages and wanted to check these seem normal? if i could hear the throttle adjustment noise i would be happy.

    Ignition Amplifier has 12v on the 4wire side but not the 5 wire output when ignition to the on position but not started
    Coilpack input wires has 0.16 0 and 12v on the 3 pins when ignition to the on position but not started
    MAF live gets 5v when ignition to the on position but not started
    Injectors have 5v ignition to the on position but not started
    Z1 gets 12v for a second when ignition on but then drops off

    wht other tests can i do to check my voltages are ok? crank it and check voltages i spose on things like the injectors?
     
  7. rubjonny

    rubjonny Administrator Staff Member Admin

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    maf and injectors would usually be on a fuel relay live, how are you testing the voltage exactly?

    make sure you see ignition and cranking 12v when testing between ecu live pin 1 and earth pin 2, also ecu pin 3 should have permanent live
     
  8. cupracraig

    cupracraig Paid Member Paid Member

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    In the garage testing now. I have ignition 12v between 1 and 2 and also perm live on 3
     
    Last edited: Nov 13, 2020
  9. cupracraig

    cupracraig Paid Member Paid Member

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    Green/red 3 to fuel relay
    Purple/white 4 G1.3
    Red/brown6 rev output
    12+13 MAF
    White/grey 19...k line
    Brown 25 02 sensor
    Black 26 02 sensor

    When I extended parts of the loom I did it one piece at a time and replaced pin for pin..so I thought. So this should just work and most of seems to be.
     
    Last edited: Nov 13, 2020
  10. cupracraig

    cupracraig Paid Member Paid Member

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    i have an old ECU and wen i power up the vag com light flshes for a few seconds then goes out and i cant connect... on my main ECU it doesnt flash at all
     
  11. rubjonny

    rubjonny Administrator Staff Member Admin

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    ok so ecu pin 3 green/red if its fed to fuel relay is wrong then, it needs permanent live not fuel pump live

    the light on the vagcom cable should be powered either from the vagcom port directly or sometimes its wired to usb power from the laptop, so sounds liek port issues or cable issue. port should have ecu grey/white to pin 7, perm live to 16 and earth to 4.
     
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  12. cupracraig

    cupracraig Paid Member Paid Member

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    all sorted now, car started and ran, thanks Jon!

    well something was up... see post below
     
    Last edited: Dec 5, 2020
  13. jhax New Member

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    Good evening, I have a CE2 converted ALH and am using a MK3 (AHU) rev counter, the car idles at ~900 RPM, however the rev counter displays 3000 RPM while idling. Is there some sort of signal adjustment that needs to be made so the signal is lowered in the rev counter?

    Thank you,
    Justin
     
  14. rubjonny

    rubjonny Administrator Staff Member Admin

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    it should work fine, double check its ecu pin 27 green/brown you've wired to G1/12. you could plug in some mk3 petrol clocks just to see? make sure you've got an earth to G1/5
     
  15. jhax New Member

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    Thank you sir, I will check both out this afternoon.
     
  16. jhax New Member

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    Okay, after moving the G1/5 ground wire to the cylinder head, the problem persists. I wonder if it has to do with the needle driver motor based on the behavior? See a video here.
     
  17. rubjonny

    rubjonny Administrator Staff Member Admin

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    possibly, do they work fine otherwise?

    maybe double check the ecu wiring make sure all the main live, ignition and earth feeds are good
     
  18. jhax New Member

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    When you say "do they work fine otherwise," what do you mean? I am 99.9% positive the ecu wiring is squared away. The car starts and runs without any fault codes being thrown.
     
  19. rubjonny

    rubjonny Administrator Staff Member Admin

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    the other functions on the cluster I mean, you could plug in petrol mk3 clocks temp just to see if it does the same as the signal and cluster calibration is the same just redline differs
     
  20. jhax New Member

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    Ah, I understand. At this point I do not have another cluster and mk3s are hard to come by these days. But I guess that that's the next logical step. Thank you.
     

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