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Need Help! Swap won't start!

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Old Aug 6, 2007 | 12:22 PM
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Default Need Help! Swap won't start!

Okay, here's the deal. It's a thirdgen ls1 swap. I'm using a 2000 M6 engine harness with a 2001 everything else harness. Everything seems to work, but the starter won't engage. Turn the key on, fuel pump kicks on, cluster lights up, but when you twist it again to start...nothing. Now, I've spliced the wires according to the sticky for swapping an M6 into an A4 car, so I'm pretty confident that it isn't a clutch start switch issue (I bypassed it actually). The BCM is out of a 99 car and the VATS is'nt disabled yet (I wanted to check to see if everything worked before I went further). I do have a couple of plugs over by the BCM that don't have a home...not sure what they go to. Off hand, one is a two pin plug with a larger purple and black wire. Thanks in advance.

Jeff
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Old Aug 6, 2007 | 12:41 PM
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Large purple wires are usually what put power to the starter to make it crank. You need to figure out where that wire goes.
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Old Aug 6, 2007 | 01:41 PM
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That's the thing...there is no plug that I can find to connect this to. All I know is that it is under the dash over by the BCM. The plug actually comes out in the same bundle of wires that connect to the BCM.

Last edited by fast377; Aug 6, 2007 at 01:47 PM.
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Old Aug 6, 2007 | 02:32 PM
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You need to get the Start position from the ignition over to the purple wire. It will have a metri-pack on it, and is about 3 feet long. It is buldled in. You can take the original wire and use that instead if you want. On the third gen, you have a purple wire from circuit 6. This thick wire is the starter wire. It should show +12V when you put the key in the start position.
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Old Aug 6, 2007 | 02:45 PM
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The lone connector that I am referring to looks like it comes over from the ignition switch area...I'll have to go check though. It looks like there should be another connector coming from under the hood...but there isn't. I am using a 4th gen dash and ALL 4th gen wiring.
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Old Aug 7, 2007 | 07:49 PM
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Please post a picture of what you are looking at.
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Old Aug 7, 2007 | 10:56 PM
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I'll get a pic up tomorrow. I really need to get this figured out...especially since I'm moving 3 states away in about 2 days.

My fuel pump has also stopped working now. I hit the key twice and the pump cycled on both times. Later on I tried it again and nothing. Can you burn up a pump that fast with no gas in the tank? I wouldn't think so, but you never know. I have not checked for voltage at the pump though...out of the 4 wires which two do I check for voltage right when you hit the key?
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Old Aug 8, 2007 | 10:03 AM
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Here is a pic of that plug. Like I said, it is right there where the BCM is and actually comes out of the same bundle of plugs for the BCM.
Attached Thumbnails Need Help!  Swap won't start!-p1010160.jpg  
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Old Aug 8, 2007 | 10:15 AM
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Being a purple wire, I believe that is a starter wire. Where does it go to? Come from?
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Old Aug 8, 2007 | 10:16 AM
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Does that purple wire read 12V only when the ignition switch is in the start position? If so, that is the guy you are looking for!
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Old Aug 8, 2007 | 11:10 AM
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67, I'll check for voltage in a few.

cam72aro, it comes from the driver's side of the dash. Where it goes is what I am trying to find out.
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Old Aug 8, 2007 | 12:11 PM
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There is no voltage on the purple wire with the key in the on position and no voltage with the key in the start position.
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Old Aug 10, 2007 | 10:48 PM
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No one has any ideas?
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Old Aug 10, 2007 | 10:52 PM
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haha hey i know what that plug in is for..lol....that goes to the blower motor inside the 4th gen cars. the motor is right beside the BCM. forget that plugin.
did you bypass the neutral safety switch??
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Old Aug 10, 2007 | 10:58 PM
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Originally Posted by andrew69_04
haha hey i know what that plug in is for..lol....that goes to the blower motor inside the 4th gen cars. the motor is right beside the BCM. forget that plugin.
did you bypass the neutral safety switch??
Son of a bitch!!! I was worried about that for nothing! Thanks for clearing that up for me....I appreciate that.

Yea, I bypassed the neutral saftey according to the instructions in the a4 to m6 swap sticky. What else would make the starter not work?
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Old Aug 10, 2007 | 11:05 PM
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when i did mine my starter would not crank and i had (everything hooked up) that people had told me. I ended up grounding 1 wire from the BCM (i believe its Dark Green (C5), my schematic says its the starter enable wire?) and it fired right up. maybe give that a shot.
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Old Aug 10, 2007 | 11:31 PM
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I'll try that in the morning...thanks for the help!
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Old Aug 10, 2007 | 11:36 PM
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also...if your using the BCM you need to wire in some resistors (in series) to the BCM that match the amount the original ignition key had that the BCM came out of. Otherwise you will get the old 3sec start and die.
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Old Aug 11, 2007 | 11:48 AM
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Where is that ground you were talking about? I have one that comes out by the BCM that connects to the lower dash mount, but it is a black wire. Is C5 the connector? If so, which connector is it?
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Old Aug 11, 2007 | 12:04 PM
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let me go look at my car....hang on
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