What would cause the dashlights and taillights fuse on a 1995 Mazda MX-6 to blow even when the fuse was just replaced?

Answer 1

A conductor [wire] is capable of carrying only a limited amount of electrical current [measured in Amps] without overheating, which could result in damage to the insulation on the wire, or in the worst case, a fire! A fuse [or circuit breaker] is a device designed to limit the flow of an excess, or dangerous amount of current. It works by "blowing" out, or melting a fine wire within the fuse. When a fuse blows, it "opens" the circuit, thus preventing the flow of current and thus protecting the wire(s) in the circuit in which it is installed. IF you are blowing newly installed fuses as soon as they are installed, or power to that circuit is turned on, then that is an indication that there is a "short circuit" somewhere in that circuit. A short circuit is a condition where an electrically energized conductor has come in contact with a "ground" [a ground wire, the vehicle frame or any metallic part of the vehicle which is in contact with the negative terminal of the battery]. To prevent the problem of repeatedly blowing newly installed fuses, it is necessary that the ground condition be found, and corrected [removed], beforeattempting to install another new fuse. Short circuits can damage or destroy expensive electrical devices, the wiring system of a vehicle, or cause a fire which could destroy the vehicle, and seriously injure or kill someone. Do-it-yourselfers should not attempt to correct short circuit porblems without knowledgible help, and it is best to have that work done by a qualified automotive electronics technician.