My 1980 D-50 up & quit a while ago , let it sit a few days & started right up & ran for 2 more days then quit figured it was the fuel pump as everything is original . Replaced fuel pump . Not the problem , no spark . Replaced coil, distributor& wires still not the problem figured it was the ESS relay swapped out with 2 different ones off of my brothers running D-50's still no spark! Undid the whole wiring harness looking for bad connections all good.
Have12 volts to coil& 12 volts out of coil but it won't light up my test light coming out of coil????? Any ideas??