When I put my truck in reverse, the backup lights no longer come on. As I understand it, my NSS is most likely out of adjustment. I crawled up under my truck earlier and noticed the lever that's bolted to the NSS is loose. By loose, I mean I could move it up and down no problem. My question is if this is a sign that the NSS is bad or is this how its suppose to operate. My truck is a 1978 w/ 351M & C6 if it matters.