What he was supposed to do is buy the new harness and plug into the old harness. The new harness must say it is for a 2004 Wrangler, and the colors will be given on the new harness. Can you reattach the old harness? Or, if you can plug in the new harness to the old cut one. The colors on the old harness will line up with new harness and you can identify it this way, using the diagram of the new harness and tracing the wire across to the old harness.