no spark from coil

Running a jumper from battery to coil + will eliminate key/ bulkhead/ harness wiring problems, is the equivalent of "hot wiring."

Using the key vs jumpering the relay causes different voltage to the ignition............Jumpering the relay still leaves the ballast in the circuit and causes low ignition voltage. If battery is low, etc, this might be enough to "not" get spark. Running a jumper wire will help that problem.

Without spare parts "on scene" this could be a problem.