no back up lights

Pull the connector off of the neutral safety switch and check the two outside terminals with a test light or volt meter. You should have voltage to both terminals with the key in the run position and the shifter in reverse. If everything checks out ok use a jumper wire to connect the two outside termials together if the lights still don't come on either both lights are burnt or you have wiring problems. I recently had the same problems with mine. Here are a few things that I had to fix. The bulb sockets had rust in both of them so I unplugged them and used a 12 gauge shotgun barrel wire brush on the end of a drill to clean out the sockets. I removed all of the wires from the plugs in the trunk and cleaned each one of those. I removed the ground wires and cleaned the terminals and sanded the spot where they mount to the trunk. I also had to end up changing my neutral safety switch.