first let me say i'm not familiar with jeeps of your vintage, BUT that item sure looks like an electrical overload, or some call them a circuit breaker. If so, inside the housing are bimetallic strips that separate (break the circuit) if heated too much by having too much current. They've been known to go bad and operate to open the circuit even though current isn't too high. You can hear them click when they reset themselves after cooling down. Hopefully it will be an easy replacement. If your system is 6v make sure you get one compatible for that voltage and the current rating.