lights don't work?

I have a 00 xj which I just installed a wiring harness to hook up my trailer. I hooked it up last weekend and all lights worked fine. Now I'm having the problem were my rear drivers light doesn't work along with the front dummy light below the head light on the drivers side. This is only the case when the lights are turned on. My rear drivers brakelight works? I checked the fuses in the engine bay but wern't sure if there are any inside the xj. Any help would be appreciated.