Toyota Repair: backup light, neutral safety switch, toyota camry

Question
I have a '93 toyota camry 4 cylinder automatic. THe backup lights are not working. I had this problem before and found out about the wire problem in the trunk near the driver's side hinge. We jiggled the wires and it came back on. That did not work this time. One of the wires was cracked, but not all the way through, but I put in a connector any way. All of the fuses are okay. I was told the backup lights are controlled by the neutral safety switch. I removed it and did not know if there is a way to test it. Is there anything to do before replacing the switch? Can you test it? Thanks

Answer
Neutral safety switch problems are rare so I would suggest that you make absolutely sure that there are no other broken wires in the harness, it may be necessary to remove all of the insulation up to where the harness enters the inside of the passenger compartment, try to pull the wires apart if they are weak or broken inside the insulation they will pull apart.