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Ignition (electrical) help please!!!

Old 07-07-2015, 09:11 AM
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mdt424
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Default Ignition (electrical) help please!!!

Hi guys,

We have a 68 Mustang with a 71 351W in it. We put a Pertronix distributor in & were told to cut the pink resistance wire to allow full 12 volts to the coil. We cut the wire, hooked everything up & instantly smoked the purple wire from the ignition all the way to the firewall & beyond (it was 1am & I could go any further). I'll trace the rest tonight. What did I do wrong? More than one person INCLUDING the Pertronix tech guy told me to just cut the pink wire. Any help would be great!
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Old 07-07-2015, 01:00 PM
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jwog666
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when u cut the wire, you must have let it touch ground, or you have a short, thats the only way to burn off a wire like that
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Old 07-07-2015, 01:37 PM
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Jwog, definitely did not touch ground battery was disconnected when I cut the wire & taped both ends. This pink wire has a green/red wire with it in the same pin. Where does it go? Any idea what the purple wire is?
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Old 07-07-2015, 01:49 PM
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jwog666
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not sure, i dont have a diagram handy of that specific car, i suggest you get a mitchell or haynes and look . the wire you hooked to then is ground, thats the only way to smoke a wire like that. good luck
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Old 07-07-2015, 02:09 PM
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Thank you! I'll keep you posted.
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Old 07-07-2015, 02:14 PM
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Starfury
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+1

You have to have shorted something to melt that wire, but you'll need a wiring diagram to figure out what it was. I strongly suggest a factory service manual as opposed to a Chilton's/Hayne's. More expensive, but worth every penny.

You can't just cut the pink wire in one spot; you have to remove the pink resistance wire (tape is not the answer here) and install a new lead from the ignition terminal to the firewall plug where it runs to the coil +. You also need to make sure you don't have any other leads attached to the coil +, except maybe one for a tach signal.
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Old 07-07-2015, 02:18 PM
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Chromeshadow
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The wiring diagram should have some with the Pertronix distributor,can you post it here?
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Old 07-07-2015, 02:30 PM
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Tad, the pink wire is in combination with a green/red wire. Do I take both those wires off & run the new one?

Chromeshadow, love that name! There was surprisingly little paper work with this distributor. I will post what I have. The car ran great with this distributor but started back firing then quit altogether after a couple weeks. Pertronix tech said the pink wire caused a slow failure due to the reduced voltage.
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Old 07-07-2015, 04:57 PM
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The pink goes to the ignition switch the red green goes to a second connector and then goes to the coil. The other side of the pink/ red-green connector goes to a brown wire that goes to the starter solenoid. When you turn the key to start, the solenoid is pulled in and not only applies 12 volts to the starter but also 12 volts to the brown wire. This in effect, jumps out the pink wire and applies 12 volts to the coil for starting. When you let go the key from start position the brown wire is disconnected and the ignition gets its power from the pink wire. The pink wire is a resistance wire to run the OEM coil on about 6.8 volts. What is the Purple wire that burned up? There is a violet wire that connects to one side of the ammeter if you have one. The ammeters in Mustangs are weird and use the wire as a shunt. The yellow wire connects to the battery side of the starter solenoid and the ammeter. The violet wire to the other side of the ammeter and the light switch /fuse box/ B on ignition switch via a black /Yellow or in some cases to a point midway on the wire that connects to the Bat terminal on the generator.
Either way you need to have some wire connect the C terminal on the ignition switch to the coil positive. You just can't cut the pink wire or you will have no power to the coil.
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Old 07-08-2015, 11:59 AM
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Thank you all, had to work until 1am & back at it today so I will apply all I've learned here tonight & update our progress. Thank you all again for your help!! My so is very eager to drive his car.
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