recently installed a Blaster 2 coil in my 71 Mustang which has a 351C-2V...followed instructions and spliced in the supplied ballast resister into the 12V red wire running to the coil...recently added a
Pertronix ignitor to the distributor (Accel 34202V-dual point-vacuum advance)...am wondering if I still should have the ballast resister in the 12V supply...I am under the impression that Fords typically have a resister wire in there somewhere although my wiring diagram is a little vague on
this...it shows a resistor wire in the wiring diagram but doesn't appear to be directly in the 12V supply to the coil....will having an extra
ballaster harm anything?? will it affect the intensity of spark delivered by the coil...should I leave it in or take it out???

Dear Sir,

Pertronix normally recommend to have a 1.5 ohm resistor to their Ignitor,the MSD Blaster Coil has already .7 ohms built in to it. You will have to measure the resistor wire, if it is a .8 ohms resistance you do not need the
resistor, but if it is no resistance you will need to put the .8 ohm resistor in line. It will damage the ignitor if too much resistance is placed in line, and will not get the full output.
Thanks,

MSD Tech

I'll try to help out with this one.

The purpose of a resister wire, or balast resister in the coil wire is to reduce the voltage to the coil while the engine is running to apprx. 6 volts. This wire or resister is bypassed while you are cranking the engine to deliver double voltage to the coil for starting. Adding extra resistance will lower the volatge to the coil, and lower the spark voltage. The only thing I would question about MSD tech's advice is why would too much resistance damage the igniter? Seems like it would just weaken the spark. I would replace your ignition wire with a new 16 ga copper wire and use the balast resister. Good luck,