back up sensors not working

I have a 2003 F-250 with the back up sensors in the rear bumper. Several weeks ago I started noticing a different than normal high pitch beep when I went into reverse and the off light coming on. Now the off light is on all the time and the sensors are not working at all. Can anyone help.:screwy:

I have an 03 F250 also and my back-up sensors beep not matter the distance. I am thinking of disconnecting the sensors one at a time to possibly isolate a bad sensor. What do you think?

Try cleaning the lenses on the sensors first. Dirt, mud, even road film, can reflect the signal and cause erratic action, or constant beeping.

I've got an '03 F350 and "OFF" light stays on for backup sensors also. Any HELP?

Have a 2006 F350, and the same thing is occurring. Strangely though, during the winter months they seem to be working 90% of the time.