There is no adapter to go from 4 pin to 7 pin or even 6 pin.
Unfortunately you will have to add a 4 pin to the trailer or add a 7 pin to Jeep.
Or if you can get a pigtail for trailer side 4 pin and tap into the existing wires on the trailer to just run the lights. If you do that you will be able to run with or without brakes depending on what vehicle you are towing with.
Last edited by owtdorz; 04-08-2009 at 06:59 AM.