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Unknown Wire & Holley Help

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Old Jun 6, 2015 | 12:08 PM
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Default Unknown Wire & Holley Help

I have a 1999 LM7 5.3 and it came complete but this wire was cut coming off of the factory coil harness. I have a Holley HP and im wondering where this green with a white stripe wire goes and what is it for. I have no power to the coils and fuel pump so do I have to program to get power?
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Old Jun 6, 2015 | 06:14 PM
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look into LT1Swap.com site he has good info. look under application list and sort thru. Pinks are usually hot. is this a harness you did? lt1 has pics on how to do the fuel pump, injectors, coils, oxygen sensors, maf sensor. look see if thats what you have going.
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Old Jun 6, 2015 | 06:55 PM
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Originally Posted by 76larkman
look into LT1Swap.com site he has good info. look under application list and sort thru. Pinks are usually hot. is this a harness you did? lt1 has pics on how to do the fuel pump, injectors, coils, oxygen sensors, maf sensor. look see if thats what you have going.
No, it is a Holley Ls1 harness but it is the original LM7 coil pack connecting harness.
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Old Jun 6, 2015 | 07:17 PM
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Cylinder #4 ign control wire is Dark Green/White stripe. That is is the only Green/White wire in the coil wiring. All pinks should be 12V with the ignition 1 relay activated and are fused through the INJA and INJB fuses in a factory setup. Black is ground. Brown or Brown/White is the low reference from the PCM and the remaining wire is the control wire for the coil, which is a different color for each cylinder.

Last edited by DrX; Jun 6, 2015 at 07:28 PM.
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Old Jun 7, 2015 | 09:28 AM
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This is a better shot of the wire im talking about. Why is it loose like this and that is the way I got the engine with all the factory wires and computer all intact.
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Old Jun 7, 2015 | 12:26 PM
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Originally Posted by Modchevelle
This is a better shot of the wire im talking about. Why is it loose like this and that is the way I got the engine with all the factory wires and computer all intact.
Shouldn't be any additional wires coming out of the harness unless someone added it to try and pick up an RPM signal. Follow it back into the coil harness.
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Old Jun 8, 2015 | 07:19 AM
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Originally Posted by DrX
Shouldn't be any additional wires coming out of the harness unless someone added it to try and pick up an RPM signal. Follow it back into the coil harness.
All factory and it has the factory style electrical tape also. I know what you mean and it was strange that it was all by itself. When I got the motor it was a complete pull from a Chevy Z71 wire harnesses. A/C, PCM, etc...
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Old Jun 8, 2015 | 08:42 AM
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Definitely not factory. Test continuity between that wire and the pins on the main connector of the coil pack harness..... to see which circuit it is connected to. Also test continuity between each of the main connector pins and the corresponding pins on the coil connectors to ensure that all circuits are intact. Get rid of that wire if all circuits are good. Browns, blacks and pinks are all shared. The other 4 wires are the individual coil control wires.
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Old Jun 8, 2015 | 12:30 PM
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DrX it is as factory as you can get. I did see a green wire on the right bank as someone posted above. Im doing other wiring now and ill check that green/white stripe wire. I called my tuner and just over the phone he said its for the tach.
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Old Jun 8, 2015 | 07:21 PM
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Originally Posted by DrX
Definitely not factory. Test continuity between that wire and the pins on the main connector of the coil pack harness..... to see which circuit it is connected to. Also test continuity between each of the main connector pins and the corresponding pins on the coil connectors to ensure that all circuits are intact. Get rid of that wire if all circuits are good. Browns, blacks and pinks are all shared. The other 4 wires are the individual coil control wires.
Drx you get the gold star. It was a soldered wire for what reason I have no idea. It was masked under the factory tape. I was wrong and I thank you for pointing me in the right direction. Now I have to wire the alternator to my 68 chevelle. Got any tips?? Thanks again DrX
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Old Jun 8, 2015 | 09:08 PM
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Originally Posted by Modchevelle
Drx you get the gold star. It was a soldered wire for what reason I have no idea. It was masked under the factory tape. I was wrong and I thank you for pointing me in the right direction. Now I have to wire the alternator to my 68 chevelle. Got any tips?? Thanks again DrX
As I stated, probably just someone looking for a signal. The tach signal actually comes from the PCM in a stock application.

Is it a 4 pin/2 wire connector on the alternator?

https://ls1tech.com/forums/conversio...or-wiring.html
Attached Thumbnails Unknown Wire & Holley Help-alternator1.jpg  

Last edited by DrX; Jun 8, 2015 at 09:33 PM.
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Old Jun 9, 2015 | 09:27 PM
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Originally Posted by DrX
As I stated, probably just someone looking for a signal. The tach signal actually comes from the PCM in a stock application.

Is it a 4 pin/2 wire connector on the alternator?

https://ls1tech.com/forums/conversio...or-wiring.html
4 pin but it had one wire. I hooked it to the brown wire that went to old external reg that was in my chevelle for gen light?
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