My backup sensors stopped working and light on dashboard switch stays lit. Any suggestions to getting them working again?

SOURCE: The dashboard light for the hand brake stays on

check the fluid level it's probably low. it's under the hood just above the brake booster

SOURCE: Off light is lit on backup sensor button in dash

Push on the button and see if the light goes out. It can be a simple off-on switch.

If that does not work the owners manual will have info on using your MENU function in your instrument cluster. When you get into the correct screen there will be listings of HORN alert with the remote, and AUTOlock for your doors. The backup function is just another item to select. Most likely someone was looking to reset the oil warning interval and accidently reprogrammed the menu.

SOURCE: 1979 Ford Bronco 400M engine. Tail lights work but

The brake light and the turn signal are the same bulb. Most of the time if the bulb on the dash stays on it is because a bulb is blown and thats the way it tells you.

SOURCE: backup sensor problems

easiest way withoout a scanner is
verify that all wire connectors to back of sensors are not noticable damage, if so repair
if no damage, buy one sensor and trial each one with known good one til light is functioning properly.
very common for sensors to fail, so if want to fix you will need to buy one and all are the same so you can inner change

otherwise you will need scanned to determine which sensor is faulty

hope this helps
Jay