Reverse lights not working

I think the transmission has a reverse switch that can go bad. Check for that. Here's a needlessly long youtube video about changing that switch.

 

Had it happen on my old International. Just ran a wire to a switch on the dash. Never had a DOT officer ask to see it on. But had the ability nonetheless.

 

I replaced one on an old 9 speed many years ago. It was on the top of the trans, just had to take the shifter boot off the floor.

 

Reverse switch has 2 wires. (1) goes to rear light bulb (2) 12 v+ that shares power with air dryer heater fuse. If fuse is blown, usually signifies that air dryer heater element is bad. Unplug air dryer heater and replace fuse if I was correct.

 

"air dryer" 15 amp fuse. Bottom right of fuse panel. 3rd from right. (edit) had brain fart in last post. (1) wire goes to rear light bulb. not ground! (2) other wire is 12v+ from fused circuit.