Caravan L4-2.4L VIN B (2003)
Accessory Delay Relay: Description and Operation
ACCESSORY RELAY
The accessory relay is an electromechanical device that switches fused battery current to the accessory powered vehicle circuits when the ignition
switch is turned to the Accessory or ON positions. The delay feature will maintain power to the accessories for 45 seconds after the ignition is shut
OFF or until a door is opened. This allows sufficient time to close windows and park the windshield wipers. The accessory relay is located in the
Integrated Power Module (IPM) in the engine compartment.
The accessory 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 accessory 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.
