94 Ranger Engine Swap Strange Problem HELP????

New to the Forum, but not new to Ford Ranger, my son and I just swapped out a 94 4L V6 non EGR'd or likely non California engine for an EGR equipped 94 4L V6 low miles complete engine. Install went smoothly EXCEPT the Ignition Key will NOT turn over the engine or engage the Starter. Fuel pump runs up etc.....but in order to start the engine we must Hot Wire the starter.....????
Swap out was done since my son drove the truck till it died and died hard when Engine Coolant leaked out totally......Grrrr

I am at a loss as to what the issue is??????

Anyone who has a solution or suggestion we are open to anything here. It should be something real simple!?!??!

GARY
Stanley Idaho
Very remote from any service assistance!!!!

Late answer, but for anyone doing this swap. If the starter works when you jump it but not with the key, the engine swap is fine and the problem is the small wire that tells the starter relay to crank. On these trucks the key's start signal goes through a safety switch (the clutch pedal switch on a manual, the neutral safety switch on an automatic) to the "S" terminal on the starter relay on the fender.

Have someone hold the key in start while you check for 12 volts at that S terminal. No voltage means the signal is stopping at the clutch or neutral switch, or at a plug that got left unplugged or pinched during the swap. Voltage there but no crank means the relay or its ground. Either way it's one wire, not the new engine.

Dana