jack, Not quite sure what year your Cherokee is one can only help with some general ideas. I would check for voltage at the bulb sockets with a multimeter. If you have voltage at the sockets and the bulbs are okay, I would think that you have a bad ground. It could also be corrosion on the contacts in the sockets. Also make sure that your light bulbs are the correct ones for the socket. Check with your owners manual on what type. There are different bulbs that can fit in the socket, but they might not make proper contact. I seem to remember that besides the fuses in the fuse boxes that there was also some inline fuses. You should also get power to your switch, again, check with a multimeter. I attached a wiring from an 88 Cherokee which might as least get you started.