I just got a new RV and having a problem hooking up the trailers light wiring harness. The trailer has a 6 plug round connector (female) and the Expy has the 4 wire flat connector (female). I have found a flat to round converter but the problem is that on the flat side is also female! and I cant seem to find anything else.
Folks are telling me I need to re-wire the Expy for the 6-plug round connector but I cant believe they dont make a simple converter out there. Does anyone have an idea before I go start cutting expy cables???

 

If you follow the wires from the 4 pin connector they will lead to a plug. I know ford sells the 7 pin (round) connector that plugs right in. Then all you have to do is attach the ground wire to the frame. No cutting involved. I mistakenly bought the wrong harness which had the 4 pin to the 7 pin connector. So I took the 4 pin connector off, used the vehicle plug side and cut and spliced to the 7 pin connector. A little heat shrink and had no problems. My brake controller works great. Good luck. Chris

 

I have just finished installing my round 7 pin connector. It was easy. I bought the 7 Pin trailer pigtail and electric brake pigtail from Ford for $120.00. A pigtail is a short section of wire ranging from about 8" to 2 feet. The rear 7 pin pigtail has molded plugs on either end for easy installation. Remove the Flat 4 pigtail and ground wire, and plug in the 7 pin and install the ground wire. The ground wire is fastend in the same location as the Flat 4. The brake pigtail plugs right in up under the dash, but needs wired to your controller.

The 7 Pin pigtail also comes with a mounting bracket.

 

My '03 had the 4 wire and the round plug. The 4 wire was wired backward when I bought it new. I did not realize I had a round plug until I got down there and looked - about 2 weeks ago.