I recently bought a good running CJ with a 304 and a glass body (but a trashed frame) to swap onto my good frame. When I went to hook everything back up I noticed that there was a ballast resistor buried on the firewall, but hooked into the ignition system. I know that the factory Duraspark system is supposed to have a built in resistor wire and no ballast resistor, but is there any way for me to test the system to find out if I really need this thing or if the Bozo I bought it from installed the resistor just because it came with the old MSD coil? Can I measure the voltage at the coil somehow and tell whether or not the ballast resistor has been "added on" or if it actually needed because the factory wire is missing/bad? I know the CJ I bought has been running for about 20,000 miles with this thing installed, but after seeing some of the PO's other "fabrication" I really doubt that this thing is needed.
Thanks.