Saturn Repair: 99 Saturn with no back-up lights, saturn dealer, light sensor

Question
I have a 99 saturn 1.9l 4-door with a 5-speed manual trans that I recently purchased with about 113,000 kms (65,000 mi).  The problem is that the back-up lights will not work either while running or with the key in the "on" position.  I have checked the wiring, bulbs, sockets and the mini-fuse(and replaced it just in case).  I know there is a vacuum-operated reverse light sensor on the side of the transmission.  My question is do I go ahead and replace the vacuum sensor (it's only $13.00 but the nearest Saturn dealer is more than 200 miles away) or could there be another reason for the failure and does the car have to be running for the back-up lights to operate?  Also, do I need to watch for anything when removing the relay or use any sealant if I replace it?  Coincidentally, when I put the car in reverse, I get static on the radio (only on weaker stations).  Don't know if that is related in any.
way.

Answer
Hi u say it is vacuum operated?ifso i have no idea but all the other ones were normal reverse switch two wires that gets ground when u put in reverse the thing to do is check for power on the battery side if good put in reverse if no power switch is bad if good there wires to lights are bad.. if its vacuum i will check monday and get back to u