Dakota Quad Cab 4WD V6-3.9L VIN X (2001)
Seat Belt Buckle Switch: Description and Operation
The seat belt switch is a small, normally open, single pole, single throw, plunger actuated, momentary switch. Only one seat belt switch is installed in the
vehicle, and it is integral to the driver seat belt retractor assembly. The seat belt switch is connected to the vehicle electrical system through a short
pigtail wire to a dedicated take out and connector of the body wire harness.
The seat belt switch cannot be adjusted or repaired and, if faulty or damaged, the entire driver seat belt and retractor unit must be replaced.
The seat belt switch is designed to control a path to ground for the seat belt switch sense input of the Electro-Mechanical Instrument Cluster (EMIC).
The seat belt switch plunger is actuated by the seat belt webbing wound onto the seat belt retractor spool. When the seat belt tip-half webbing is pulled
out of the retractor far enough to engage the seat belt buckle-half, the switch plunger is extended and closes the seat belt switch sense circuit to ground;
and, when the seat belt tip-half webbing is wound onto the retractor the switch plunger is depressed, opening the ground path. The EMIC monitors the
seat belt switch status, then controls the seatbelt indicator and sends electronic chime request messages over the Programmable Communications
Interface PCI data bus to the Central Timer Module (CTM) based upon that input.
The seat belt switch receives ground through its pigtail wire connection to the body wire harness from another take out of the body wire harness. An
eyelet terminal connector on that ground take out is secured under a ground screw to the left lower B-pillar, The seat belt switch is connected in series
between ground and the seat belt switch sense input of the EMIC.
