Only one reverse light works

As the title states, only one of my reverse lights works. I replaced the bulb, still doesn't work and I checked voltage at the bulb socket and there is 0V when in reverse. So this is obviously a problem with the wiring harness. My question is, does the passenger side reverse light wire get spliced into the main harness by the drivers side taillight or does the wire run all the way back to the fuse block? Any other suggestions are welcome

 

Bump, anyone?

 

I bet it’s a probably with corrosion in the wires on the back of the taillight housing

 

^

That was my first thought too

 

Yeahhhh they’re pretty crusty alright, I’ll try and get a voltage reading on the back of the house if I can. Might have to strip back the wires a bit

 

>90% of electrical issues like this relate to a bad ground. Get an incandescent bulb style test light and check your grounds.

 

Update: took apart the tail light and there was voltage at the pigtail connector... so I plugged it back in and it worked. Before reassembling I sprayed the connectors down with electronic contact cleaner and then packed dielectric grease around the connectors after plugging back in.