Relays and Modules - Starting and Charging - Starter Relay Location
Starter Relay: Description and Operation
RELAY - STARTER MOTOR
DESCRIPTION
The starter relay is an electromechanical device that switches battery current to the pull-in coil of the starter solenoid when the ignition switch is turned
to the Start position. The starter relay is located in the Power Distribution Center (PDC) in the engine compartment. See the PDC cover for relay
identification and location.
The starter relay is a International Standards Organization (ISO) relay. Relays conforming to ISO specifications have common physical dimensions,
current capacities, terminal patterns, and terminal functions. The starter relay cannot be repaired or adjusted. If faulty or damaged, it must be replaced.
OPERATION
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 electromagnetic coil is energized, it draws the
movable contact away from normally closed fixed contact, and holds it against the other (normally open)fixed contact.
When electromagnetic coil is de-energized, spring pressure returns movable contact to normally closed position. The resistor or diode is connected in
parallel with electromagnetic coil within relay, and helps to dissipate voltage spikes produced when coil is de-energized.
