no back up lights

it looks like a female round plug, kinda like the one for the licence plate light. I did check the bulbs one was blown out so I bought a new pair, cleaned up the terminals and connections and put dielectric grease in them

OK, but WHERE IS IT, engine room, under dash, trunk, etc?

If it's up front it could be the left fender mount indicator

Did it have the optional "road lamps?"