I checked the fuse (which also controls the A/C,etc , all of which are working). I changed the bulbs. What else is there- I believe there is a switch just like the turn signals have a control switch ?

There is a switch on the transaxle, usually at or near the swift quadrant box. Should see a connector with wires. Screws into the transaxle. Could also be a broken wire or loose connector. $25 or so for the switch.

Simple electrical system means it will be a simple fault. Likely the Reverse Switch itself or a common ground. If you can't trace the power flow, I'd start with the switch.