I have been reading everywhere and seems my situation is slightly different. I cannot remember the last time my backup lights turned on. My running lights and brake lights work as well as turn signals. I have:

• Replaced bulbs
• checked for power at the connections (no power)
• checked the fuse 70 inside the cab (good reading around 12v)
• and checked fuses in the engine bay (all have power)
• Metered the trailer backup relay 76 (0V on all pins except 3 has 14V)also the relay was turned around with 5 in the 3 slot

Am I down to just chasing the wiring or am I missing something here?

 

Bench test the reverse relay it should be under your hood. You can also borrow the exact same relay from another slot for testing purpose.

 

bench tested it with the fuel pump relay and no luck.

 

Don't know if your vehicle has auto trans or manual trans. Verify power is available at back up light sw assy if manual trans, and if power comes out of it when reverse is selected at sw on MLPS on auto trans.