Hitch Help!

Hey guys,

I've got a very weird trailer lighting issue on my 2004 Outback. Having installed a hitch on my new car, I took the wiring harness from my old (1997 outback) and plugged it in to see if it worked. I tested it on a trailer and it seemed to work. Now, a couple of months later, when I'm ready to go on a trip, only the left turn signal works. No Brakes, no taillights.

Of course I figured it was the trailer lights, having tested the harness on a different trailer before. Not so. I brought home a complete kit for re-wiring the trailer, installed it, only to find the problem is unchanged. I tested the new lighting on a different tow vehicle, and all the lights work.

Back to searching for a wiring harness- All the aftermarket harness suppliers in my area say their 2004 harness books only show one harness kit for 1996-2003 outbacks, and the same kit works for 1998-2004 Foresters. They show no part numbers for 2004 outbacks.

The Original Subaru harness from my dealer costs $92.50. Did they change something from the 2003 Outback to the 2004 outback that requires a new harness? What the heck is going on here?

Thanks much.