That sounds like the resistor wire I am talking about. Not sure on the color, but pretty sure I remember reading about it being used on the DS2 setup.
I know when we made our own wiring harness for that Cobra replica, we had several DS2 module failures, and adding a ballast resistor solved that. It wasn't fun changing a DS2 box on that car, cause we located in a hard to reach location, once the body was on the frame. Looked like a real good spot beforehand.......

 

Jim posted a good link in Post #9 above; I haven't read it thoroughly but, on the outset, it looks helpful.

There might be some stuff in the sticky about this, too, not sure.

 

There are three threads in Horsepuller's stickies.

Ford Truck Enthusiasts Forums - View Single Post - '80-'86 Tech Tips, Tricks and Projects:

 

I took the 2 pole ballast resister from a 60's mopar, and ran the wire that would go to plus on the coil to one side, then from the other side, I ran it to the plus on the coil.I did this 10 years ago when I converted my farmall to 12 volts. It works fine still.

 

I added the resistor (1.35ohms) to the coil it missed like crazy and the engine died after about 30 seconds. I took the resistor out and it ran fine, with full voltage. I am once again banging my haed against the wall. here is how i have it wired:
+Batt>30A kill switch>splice into 2 one going to control box and the other to ballast resistor then coil

 

It should work wired that way.
Are you seeing 7V +/- at the coil???

 

make sure the coil you are using says external resistor only when you use a ballast resistor

 

Isn't this a DS-II engine from a 351 pickup with the horseshoe connector at the coil????

 

it was getting 7.3V its an accel superstock pn# 8140C i cant find info on it

 

I'm sorry. I can't say I have any personal experience with Accel SuperStock coils.

It may be that the low resistance of the 8140 aftermarket coil is overheating the control box.

FWIW,
The 8145 is recommended for breakerless ignitions and the 140207 is the one specifically designed for high performance DS-II applications using the horseshoe connector.
FORD CANISTER DURA-SPARK RACING COIL - ACCEL Coils & Accessories - ACCEL

 

I tend to support that diagnosis, and suggest going back to a Ford OEM coil and see if your problems go away.

 

well i gave up and bought a msd street fire ignition box and problem solved, hasnt given me a problem... as for better performance dont see much however my fuel economy is up by 1.2 MPG