Let’s assume your car or light truck is plagued with a lamp or two that isn’t working properly. Where exactly do you begin? Let’s start at the beginning and examine how the lighting circuits work.
The headlight circuit is comprised of the headlight switch, a circuit breaker or the dimmer switch, and the headlights. Simple enough. If the lights fail to switch from high beam to low beam, or if they go out entirely when the dimmer switch is engaged, the problem is in the dimmer switch. In years gone by, the dimmer switch was