No Spark to Coil during startup

[Derrick]

Hello. Just did a 302 swap in '71 F100. Prior to swap, start-up of old engine work fine. Now during start-up of new engine, + side of coil not getting spark. We have started engine running a direct wire from battery to + coil. We have tested i-terminal of solenoid and it sends current to brown wire during start-up. So I believe we've narrowed it down to wiring/connections between solenoid & coil. With switch on, wire that plugs into + coil show intermittant spark, which I believe is correct. However when switch is turned to start position, the intermittant spark goes to nothing. Its my understanding I should get a full 12v from this wire during startup. In reading posts here, the brown wire runs from i-terminal of solenoid and joins up with resistor wire from ignition switch to + coil. I have not started untaping the wiring bundle under dash to trace this brown wire all the way since it worked before engine swap. Is there anything where brown wire & wire from switch meet that I should check? Thanks in advance for your help. Derrick.

[Ranchero50]

Take your instrument cluster out. The wire for the cigar lighter is close to the joint for the big pink resistor wire and the brown hot in start wire.