Need a ballast resistor?

[lightnin-boy]

I just replaced my Crane coil with a stock Ford TFI coil. From what I've read this coil is fine with a full 12V powering it. So What I did is pulled my dash cluster and spliced a wire in ahead of the pink resistor wire to power the coil and the Duraspark module. The car fired right up and idled fine. I left it running in my laneway and after a few minutes I could hear an audible click coming from the coil. This continued until the car cut out and wouldn't restart. Checking the coil at this point, it was very warm to the touch. I had a spare popped in place and the car started again. This kind of tells me that the coil is drawing excessive current. Checking some wiring diagrams from cars equiped with TFI it looks like the coil's voltage is supplied by the TFI module itself. Is the module providing current control as well?

I'm not sure what to do here... Anyone else running a TFI coil with a Duraspark or GM module?

Kirk

 

[Lazy JW]

Someone posted on here long ago that a Red grommet Duraspark module could handle the extra current draw of the TFI coil. I dunno.

The standard Blue grommet Duraspark module is really NOT intended for that high current draw. Some folks have successfully used it but I don't recommend this.

The schematics in my manual show a ballast resistor used with the earlier DS2 systems but the later schematics do NOT show the resistor. Go figure. They all use the old style coil rather than the TFI type.

I am running a DS2 triggered GM HEI module with a TFI coil in my F-350 and am NOT running a resistor. No problems thus far.

Check out www.gofastforless.com for more info.
Joe