72 dart harness

There is a difference from 70/71 and 72. I put a 70 dart dash and harness into my 72 valiant and used the 72 harness from the bulkhead into the fire wall. It was a while back but I know that the horn wire and the ignition to the starter silinoid feed wire are swapped on the two. I could not start my car then my 3 year old son was inside and hitting the horn and the car was turnning over?? I checked the wire diagram in the chilton manual and that was the case. I just swapped the two.