Hello, Apparently, the 85 blazer distributer and coil are very unique and not shared with other model years. mine has a vacuum advance, ignition module in the distrib and no ECU. After an engine swap, my wires are messed up. Trying to trace it is proving difficult as the only reference i have is a haynes. Every wire diagram in the haynes shows an ECU. The problem is no spark. Out of two known running engines (one was banging like mad) with two known good distributers I doubt both ignition modules decided it was time to fail simultaneously. I did swap the two I had, but figure going out to buy another is a waste of time. So, I am trying to figure out what is disconnected. On one side of the coil is a wire that goes to the distributer and it plugs into the ignition module. The other side has two wires, one of which measures 12V to ground. I am not sure of the other wire, where it goes or if it is supposed to be grounded. Any help or reference to a wireing diagram specific to the 85 would be helpful.