No Spark

[Jacal57]

I have a 85" CJ7, 258 ci, that has no spark from the coil. I had a comple wiring harness melt down and bought a wiring harness from Painless Wiring. I rewired the entire jeep and had it running for three weeks when out driving it quit running. I have no spark at the coil, I replaced it, the ignition module, rotor, cap, distributor pickup, solenoid, even the ignition switch. Still no spark. The coil has 12 volts on both sides of the coil when the ignition is in the run position. All conections are solid nothing is loose. Motor turns over with no problem. Anyone have a suggestion?

 

[ka041a]

12 volts on both sides of the coil? only some european cars, that i know of, operate on 12 volts at the coil. there should be either a resistance wire or a ballast resistor between the coil pos terminal and 12volt power, because full battery voltage will burn out the coil fairly quickly. also, i don't remember ever checking the voltage at the neg. terminal of the coil, but that doesn't sound right. that would mean the electronic engine control unit is somehow supplying full battery voltage! because it sparks the coil by switching the ground connection on and off, right? john