What year Spridget?
Mike, I put in a different plunger as this is a Smoothcase and never got it to work. Lights stayed on all of the time so I just disconnected. I've got as spare ribcase i nthe back of the garage to go with a 1275 that will eventually replace the '66 1098 that came with my '68. That's the least of my issues, a nit in the greater scheme of things.
Once I get the new top installed and I can actuallt see out the back window, a zip out window at that, the need for reverse lights will definitely go down.