Low Voltage to the coil

Latest development. We have determined that with the negative wire disconnected from the coil we have the correct voltage at the positive terminal of the coil. When we connect the negative wire the voltage drops to 3.5.

Now we have determined that I have the incorrect ballast resistor for the Blaster 2 coil. I need a .8 ballast resistor for this coil application. I can only find the .8 in the 2 pin configuration.

Can I change from a four pin ballast to a two pin configuration and if so how??

HELP...