Help My Daughter's Graduation Gift Won't Start

A 2002+ Mustang V6 has in intake manifold runner control (IMRC). A 2000 V6 does not.

A 2001+ Mustang V6 uses a cylinder head temperature sensor(CHT). Where as a 2000 V6 uses an engine coolant temperature sensor (ECT).

A 2000 Mustang V6 has an air injection module where as a 2003 does not.

I can also recall that somewhere along the line Ford made changes in the V6 coil pack. IE the V6 Mustang did not use the same coil pack across the entire model year range.

Look at the compatibility tab and note that the same coil does not cover the model year range. Looks like the change was made in 2001 MY. Looking at the picture you can even see that the connector on the coil is different.

http://www.oreillyauto.com/site/c/d..._499&keyword=ignition+coils#compatibilityTab_

http://www.oreillyauto.com/site/c/d..._499&keyword=ignition+coils#compatibilityTab_

There are at least two differences in the engine wiring harness that I can think of off the top of my head. For you to use the engine wiring harness from a 2000 in a 2003 MY application would require a pin by pin comparison between the two model years. A set of wiring diagrams would be a HUGE help for such a task.

If interested in getting a copy for yourself I maybe able to help. PM if interested.

Or it might be easier to put the wiring harness from the 2003 motor onto the 2000 motor (be sure to use the 2003 MY coil). This still leaves what to do with the ECT/CHT and IMRC. But at least it might start.

Note, in researching this reply I didn't compare the two model year's pin outs. It's quite possible that they are very close and that your motor isn't starting for another reason. IMO the question about the differences in wiring harness is a valid question that bears some research.