Back in the 70's there was a short lived adenveture series, in which Earth was almost destroyed after a nuclear disaster... 3 people (1 elderly, a young man and a young woman, and a monkey) rode along the USA with a BOX on wheels... they wore (I think) Red & White uniform, and used a mirror and sun-beams as weapons... does it ring a bel?!
Was the "monkey" actually a chimpanzee? Was the "BOX" actually a "a futuristic-looking six-wheeled combination RV and mobile laboratory"? If so, then you're probably thinking of Ark II, (1976).