Anyone know what this wire is that I smoked?

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Corrupt_Reverend

Corrupt_Reverend

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Finally got the new shifter in and the freshly rebuilt trans filled with fluid.

Went to start and after cranking a couple times, I saw a bunch of smoke!

Pulled the key and ran around to see what happened.

One wire that comes from the resistor had totally roasted.

Here's a picture of the wire at the resistor connection:

BzxxCqol.jpg


It's the left-most wire. You can kind of see the toasty insulation.

I tracked it and it ended in a cut:

fz74PKol.jpg


Now, I'm not sure when that wire was cut. It may have been something the PO had done at some point and I just never noticed. If that's the case, I'm guessing his hack-job shorted on the firewall. Maybe had something to do with the factory A/C before the PO removed it? (Not sure why a/c would need ignition power?)

It's also possible that it got cut somehow in the madness of removing and reinstalling the transmission. I don't think that's what happened. I was really careful to make sure nothing got pinched etc. but it's still possible. I can't find anything else cut that it would have been part of though.

So does anyone know where that wire is supposed to run?

Thanks in advance!

~Rev.
 
Don't know. Did it at least give you a buzz?
 
It might be helpful if we knew what model the car was.

You know....like to try and look it up in a manual.
 
hah! That probably would help, eh?

I even told myself to include that in the OP, but forgot. Doh!

It's a '72 dart custom sedan. 318, a-904
 
You might want to shine a light down the backside and see if the missing part is clamped between the block and the bellhouse, out behind the dizzy
The automatic choke heater gets its power from that circuit, as well as a throttle kicker.
 
Checked along the bellhousing first thing. Nada.

If it's for factory choke heater, it would make sense, because that stuff is gone.

I'm guessing that the PO just chopped the wires, and I just happen to have been lucky that it didn't short out until today when I was paying attention with the hood up.
 
I highly doubt that enough current would flow through that wire to cook it , if it were just dangling against the painted firewall. I am reasonably certain that there is more to this story, than what I am seeing. Good hunting.
Ive been wrong before. But Im pretty sure about this.
 
That doesn't look like factory wiring, the only way to find what it does, is to trace it...
 
One end goes to the resistor, and the other end is cut.

I'm heavily leaning toward it being something that was removed since I can't find any other cut wires.

It could have shorted to the aluminum intake, or the pass side head.

Whatever it was for, it seems that it was not needed since everything seems dandy without it.
 
Yeabutt, if you look at where it plugs onto the resistor, that sure looks like an OEM type plug/connecter/wire/thingamajiggy......

Also, look at the bottom left corner of your red line. There is a DK Blue wire connected to the DK Blue wire coming of the Resistor. In actual practice, that junction could have been at the Resistor, rather than in the middle of the wire.

Schematics didn't always match the physical wiring........

My bet, is, that is the missing Link so to speak..........
 
Corrupt_Reverend said:
One end goes to the resistor, and the other end is cut.
...
Click to expand...
It appears that people are asking you to trace the wire that goes thru the firewall. Where does it terminate inside the cabin? The factory AC should have been powered from the ACC feed, which is in the dash. For some reason, someone ran from the IGN circuit (after the ballast?), back into the firewall. Perhaps for a custom ignition box or a tach (though tach's usually connect to coil- I think).
 
It doesn't go through the firewall. It just goes from the resistor, across the engine bay, and ends at the cut on the passenger side behind the head.
 
It might be my old eyes, but it looks like more than one wire in that bundle on the passenger side cut.
 
Re-examine the connection at the ballast: the original 2 blues wires look to go to the original connector that is plugged INTO the adapter from which the burnt wire is routed. If so, unplug the original connector, pull the adapter off of the ballast, and plug the original connector back into the ballast.
 
Corrupt_Reverend said:
It doesn't go through the firewall. It just goes from the resistor, across the engine bay, and ends at the cut on the passenger side behind the head.
Click to expand...

It looks like someone added something on to that circuit at one time, and then it was removed later.

If that wire was just hanging by the firewall, then it may have shorted to cause the burnt wire.

I would just remove it from at the ballast resistor and keep the two original blue wires going into the ballast resistor.

That would be a good feed for an electric choke for a carb.
 
Thought the 72 and up came from the factory with electronic ignition and that they used a dual element resistor. At some later point the control boxes were changed from 5 pin to 4 pin and one power wire was eliminated. Could that be what you're seeing?
 
Steve A said:
Thought the 72 and up came from the factory with electronic ignition and that they used a dual element resistor. At some later point the control boxes were changed from 5 pin to 4 pin and one power wire was eliminated. Could that be what you're seeing?
Click to expand...

Fuzzy in my mind, anymore, but the shop manual seems to think they were an option.
 
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