Trailer wiring

[beelsamin]

I've just installed the factory wiring harness for towing in my 2003 PT. I assumed, for some reason, that it would work immediately with my standard 4 way trailer harness...um no it won't.
I have gone over all my connections and they are exactly as the instructions show.I have been told that after spending $165.00 on this damn harness that I need an adapter to make the trailer signals work ???? I was told the factory harness had a converter built in...
If anyone has any experience with the PT factory trailer wiring harness I'd love their advice....I am not a happy camper

[gonzomania]

Mine is not factory, installed by a trailer hitch place. Mine has an inverter of some kind that goes from the lighting wiring to the plug for the trailer.

[Capt Kidd]

[8)]something must be hooked up wrong because I installed the factory harness in both my 01 and 05 and they work just fine with all my trailers. In my 74 Toyota Land Cruiser I did have to use a adapter that I got from U-haul but not in the PTs.