No Ballast, hot coil

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harvenator

harvenator

A fish called Wanda
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The previious owner of my 65 Barracuda removed the ballast resistor and wired the start and run wires under the dash together. He installed a NAPA Echlin gold box ecu and retained the stock coil.
This system seemed to work well for the /6 but not for the 273 I built and installed.

I'm currently using a ProForm dizzy with a coil that does NOT require a ballast resistor, initial of 10 deg and no vacuum advance (still playing with the adjustment to make that work). Seems that after I drive for about 20 mins (engine temp about 190), I lose power in the 3000 and up rpm range and the coil seems to be pretty hot.

I've checked the carb and filter for trash and obstructions with nothing noted.

At this point I'm not sure what to do so I figured I'd put this to the forum and see what has worked for others with the same set up. I'm limited on what I can spend otherwise I would have gone with a Pertronix system.

Anyone??
 
If you "actually" have a coil made for "no ballast" there should be no problem. Just how hot does it get?

Otherwise, you may be mistaken that the coil needs no ballast. You have a brand/ part no?

You say you don't have much money, I'd do one of two things--

either fix the wiring, and wire up a stock Mopar ballast, or adapt a GM HEI module

If you wire up a Mopar ballast, the first thing you'll have to do is figure out whether the NAPA box you have is a so called "5 pin" or "4 pin" box

Four pin boxes MAY HAVE 5 pins in the connector, the 5th pin is just not connected.

A 4 pin box can use EITHER a 4 or 2 terminal ballast --it's just that the other half of the ballast is not connected

A 5 pin box MUST use a 4 terminal ballast.

You should be able to fix the wiring, we can probably help walk you through that. It's only two wires, coming from the key, the "dark blue" run/ ign1 wire and the brown resistor bypass "ign2" wire. They originally went directly from the ign switch through the bulkhead, to the coil resistor. Dark blue goes to the "input" end of the coil resistor and also supplies the regulator, and brown goes to the coil + side of the resistor.
 
Yes, the coil is specifically for non ballast use ad is marked as such. I'm just trying to figure out the loss of power thing and thought it might have something to do with the coil but am starting to lean toward replacing the ECU. Think I'm going to swap out the coil first. I have some others that are for ballast use bit know I can run them for a while with no ballast.
I don't mind rewiring, just don't want to mess with all those fragile wires just yet. I'd rather wait and get a new harness.
 
Just ordered a TP85 module to replace the TP70 that's obsolete. No ballast required according to the wiring diagram. This is an lx405 clone.
 
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