We just did a swap from automatic to manual in our Mustang. Even the wiring harness for the whole car was swapped, and it won't start. Brake lights, headlights, and interior roof lights come on, but no accessories and no cranking of the engine - don't even hear the fuel pump priming. The transmission and engine were moved together (as in never separated from one another while moving from the donor car to the new car). Literally everything in the car is from the manual donor GT. Any suggestions? Thx.