Advice on wiring custom starter and ignition circuit.

Discussion in 'Track Prep & Tech' started by Bruce T, Nov 21, 2013.

  1. Bruce T Forum Member

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    Hoping someone with a bit more know-how and experience in these things could point me in the right direction.

    I'm in the process of wiring my accessory switch panel in the golf, (for fans, lights, etc) which includes an FIA spec battery master switch, ignition switch and a momentary starter switch, removing the OE ignition barrel switch. I'm still using the CE2 fuse box as I can afford a full race spec loom and fusebox :cry:

    I've drawn up a a circuit diagram for how I think it should be connected but would just like some guidance to make sure I'm heading in the right direction. Hopefully someone can make sense if it lol

    [​IMG]

    Any help muchos appreciated :thumbup:
     
  2. Jon Olds Forum Junkie

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    The auxiliary contact on the FIA cutout caught my eye. I used to wire them to short the alternator output to earth when the switch was operated. To collapse the system volts. Seemed to work, until I put on a 100A plus alternator. If I had bothered to read the instructions (doh) it seems the supplier wants you to earth the LT switched side of the coil to kill the engine, Seems sensible. Morale of the story, don't throw the instructions away with the packaging. LOL
    Jon
     
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  3. Bruce T Forum Member

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    Its funny you should say that Jon as I "miss-placed" my instructions and had to rummage around the bin in the garage to find them...with no luck! God bless the Google, found a handy diagram showing the connections. Here

    It think I've shown it correctly in my drawing, with the aux contact thats normally closed when the isolator is in the ON position connected to the feed for terminal 15 of the coil? The other contact is normally open and discharges the electrical system to ground via the 3 ohm resistor when engine is killed.

    The bit I'm not sure about is the ignition and starter circuit.
    As far as I can tell the original ignition switch, in position #1, takes the permanent 12 volt supply from the fuse box on termnial 30 and switches is to terminal 15 for the ignition and to X (i think this is something to do with the relief relay or something?!). Position #2 applies 12v from terminal 30 to terminal 50 for the starter solenoid.

    [​IMG]

    I would just like to clarify that what I've done with the relays in my diagram is ok/will work.

    Thanks,Bruce.
     
  4. rubjonny

    rubjonny Administrator Admin

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    ign switch:
    30 - live input
    50 - starter
    X - x-over relay trigger (blower, lights, wipers etc)
    15 - ignition live
    SU - key in ignition live (radio, lights on warning if rollout/mk3)
    P - parking lights

    there is actually no need to relay the X contact if you keep the std fusebox as this already has its own relay (#18) anyway :thumbup:

    Oh and no need to run your ignition or coil thru the FIA switch as if you kill the live input to the fusebox this will kill your ignition as well since all power for fusebox comes from the battery live to Y spade block anyway

    edit: ah no, I'm being silly the fusebox live is after the kill switch and so could be fed from alternator if engine is still running, my bad :lol:

    edit2:so yes, as per your diagram will be perfect, kill the ignition pin 15 and you kill the coil plus anything else that is triggered by it (ecu, ecu relay, fuel pump relay etc)
     
    Last edited: Nov 22, 2013
  5. Bruce T Forum Member

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    Thats brilliant, just what I was after, thanks RJ! :thumbup:

    So what do you thinm would be the best thing to do with the x cross over relay trigger? I assume it just needs 12v switched to it?

    Thanks,
    Bruce
     
  6. rubjonny

    rubjonny Administrator Admin

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    the x contact is live only with ignition but not cranking, this is so that high load devices are switched off when crankign so the starter gets maximum power. its fine to just have your x relay ignition triggered, all you need to do is remember to have the lights, wipers, blowers etc switched off before you crank the car ;)
     
  7. Bruce T Forum Member

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    Ah I see, so on the orginal ignition switch the the contact for X is only made when the key is in position 1?
    Ok so I could power it as per the diagram above, switch it directly, or just link a ignition live to H1/3 at the back of the fuse box?
    Lights, blower etc. will be switched with separate toggles via my panel so shouldn't be too hard to remember to have those switched off when cranking.
     
  8. rubjonny

    rubjonny Administrator Admin

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    yes exactly, you can do any of the above really its up to you. as i say theres no need to relay the old output from x since this is already done at the fusebox but there is no harm if you do so :)

    you could run it from the ign relay output if you like, straight from ign switch, jump it from any random ign live feed from fusebox etc entirely up to you. you could even add a relay which takes feeds from starter and ign relays to disable the x feed when cranking, but tbh that would be a waste of effort and add un-needed weight really when you could just make sure non of your other switches are on ;)

    even if you did have the other gear on the worst case car would just crank over a bit slower, and tbh it probably would still start fine anyway!
     
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  9. Bruce T Forum Member

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    Awesome! Thanks again John for the replies here and my PM :thumbup:

    Yeah I was going to mention about relaying it like you said with feeds from both circuits but decided that would be a bit OTT lol

    Where would you recommend to purchase new crimp terminals for the CE2 fuse box? Not sure what they're called, the ones found in the H1 etc etc.

    And i'm also looking for a nice locking connector to connect the panel to the interior loom so it doesnt have to be hard-wired. Maybe something like this?

    [​IMG]
     
  10. rubjonny

    rubjonny Administrator Admin

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  11. sparrow Paid Member Paid Member

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    I want to turn my crossover relay in to an ignition live.
    Is it as simple as cutting the BY wire from X (H1/3), and splicing it in to the wire running to pin 15 (H1/4)?

    The reason for doing this is I'm powering my USB hub off the old rear heater wire (plug P, the BY wire on pin 2). This is a chunky wire, so should be able to handle a few amps. I need a few amps as I'm powering two phones, and external GPS receiver and and external BT dongle already, with more to come.

    Ideally what I'd like to do is pull the pin from H1/3, and plug it in to an ignition live pin, but I can't find another one that big. All the pins on block D are too small, so I'm reluctant to splice it in to one of those.
     
  12. rubjonny

    rubjonny Administrator Admin

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    aye this would work, just be aware though if you cut the X wire this means the headlights will also be powered from your 15 ignition switch terminal, which may put a bit too much load on your ignition circuit. it depends what ignition loads you have on there though, plus if you fit a relay light loom that will drop this load off the ignition circuit and put it straight off the battery :)

    if you do go for a headlight relay kit then any ignition live to H1/3 will do as no load will then be placed on it, all it will be doing is triggerign your X relay.

    an alternative solution if you dont want a headlight relay kit and dont mine reducing the 'modularity' of the ce2 loom is run the ignition switch pin X directly to pin X of the headlight switch after removing the headlight switch wire to R/10. This will mean all the headlight loom load will run off ign switch pin X as per stock, and H1/3 can then be used to just trigger the X relay :thumbup:
     
  13. sparrow Paid Member Paid Member

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    Hmm. With all the extra devices I'm adding to ignition live, I think my suggestion may be a step too far.

    I like your last option. Just to make sure I have understood correctly.

    • Remove pin R10 from plug, and tie it up out the way
    • Cut the BY X wire from the ignition switch, and splice it in to the wire connected to Pin X on the headlight switch
    • Run a wire from an ignition live to pin H1/3, splicing it in to the existing BY wire on H1/3
     
  14. rubjonny

    rubjonny Administrator Admin

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    Yep you got it :)

    But IIRC the pins on the headlight switch are the same as the fusebox end on the ignition switch pin X, if so you could pop it out and pop straight to the headlight switch to save choppy splicey. this way you can also revert to standard again if you want :) take the headlight switch X to R/10 out completely and store it in case you want to go back, or reuse for other wiring projects :thumbup:

    then any old ignition live to H1/3 will do as it will now have no real load on it, once the headlight switch X wire is removed it'll just be the trigger to power up your X relay :)
     
  15. sparrow Paid Member Paid Member

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    Awesome, thanks. I'll trace back the headlight switch wire, and see what's what. I'll probably leave it until after Bedford next week though, I don't fancy trying to find spare wiring looms at short notice!! lol
     

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