Grand Cherokee 2WD V8-4.7L VIN N (2000)
Cigarette Lighter Relay: Description and Operation
The cigar lighter relay is an electromechanical device that switches fused battery current to the cigar lighter when the ignition switch is turned to the
Accessory or On positions. The cigar lighter relay is located in the junction block, below the driver side of the instrument panel in the passenger
compartment.The cigar lighter relay is a International Standards Organization (ISO) relay. Relays conforming to the ISO specifications have common
physical dimensions, current capacities, terminal patterns, and terminal functions.
The cigar lighter relay cannot be repaired or adjusted and, if faulty or damaged, it must be replaced.
The ISO relay consists of an electromagnetic coil, a resistor or diode, and three (two fixed and one movable) electrical contacts. The movable (common
feed) relay contact is held against one of the fixed contacts (normally closed) by spring pressure. When the electromagnetic coil is energized, it draws the
movable contact away from the normally closed fixed contact, and holds it against the other (normally open) fixed contact.
When the electromagnetic coil is de-energized, spring pressure returns the movable contact to the normally closed position. The resistor or diode is
connected in parallel with the electromagnetic coil in the relay, and helps to dissipate voltage spikes that are produced when the coil is de-energized.
