I have a 78 f150, automatic with a 351M. My backup lights have never worked in the last 5 yrs. The bulbs are fine. I'm guessing that the switch is bad. Where is it at, in the dash, on the tranny, I have no idea. Any help would be greatly appreciated.

 

It should be on the tranny, reverse sensor switch is what i think
its called, your local auto parts store can tell ya when you go to
buy the part...

 

Found it. Thanks a lot!