1997 Toyota camry

Hi,

HELP!!!! I am trying to fix a friends car. His backup lights are not working. I think I check the circuit properly. I am not a mechanic, but trying to learn automotive diagnosis, I turn the key to on position and with my power probe I went back to the trunk took the bulb out of the connector and got ground on both terminals of the connector. So I had someone start the car and placed the shfter in reverse and I checked the circuit again. It had voltage on both terminals of the connector. Is the circuit fin? The bulbs work when I checked them with the power probe. Again Help