Seat Belt Tensioner Description - Dodge RAM 1500 1998 Owner's Manual

8O - 52 RESTRAINTS
SEAT BELT SWITCH (Continued)
WARNING: TO AVOID PERSONAL INJURY OR
DEATH, ON VEHICLES EQUIPPED WITH AIRBAGS,
DISABLE THE SUPPLEMENTAL RESTRAINT SYS-
TEM BEFORE ATTEMPTING
WHEEL, STEERING COLUMN, AIRBAG, SEAT BELT
TENSIONER, IMPACT SENSOR, OR INSTRUMENT
PANEL COMPONENT DIAGNOSIS OR SERVICE.
DISCONNECT AND ISOLATE THE BATTERY NEGA-
TIVE (GROUND) CABLE, THEN WAIT TWO MINUTES
FOR THE SYSTEM CAPACITOR TO DISCHARGE
BEFORE PERFORMING FURTHER DIAGNOSIS OR
SERVICE. THIS IS THE ONLY SURE WAY TO DIS-
ABLE THE SUPPLEMENTAL RESTRAINT SYSTEM.
FAILURE TO TAKE THE PROPER PRECAUTIONS
COULD RESULT IN ACCIDENTAL AIRBAG DEPLOY-
MENT.
(1) Disconnect and isolate the battery negative
cable. Disconnect the seat belt switch pigtail wire
connector from the seat wire harness connector for
the seat belt switch on the inboard side of the driver
side front seat forward of the seat belt buckle-half
anchor. Check for continuity between the seat belt
switch sense circuit and the ground circuit cavities of
the seat belt switch pigtail wire connector. There
should be continuity with the seat belt buckled, and
no continuity with the seat belt unbuckled. If OK, go
to Step 2. If not OK, replace the faulty front seat belt
buckle-half assembly.
(2) Check for continuity between the ground cir-
cuit cavity in the seat wire harness connector for the
seat belt switch and a good ground. There should be
continuity. If OK, go to Step 3. If not OK, repair the
open ground circuit to ground (G301) as required.
(3) Remove the instrument cluster from the instru-
ment panel. Check for continuity between the seat
belt switch sense circuit cavity of the seat wire har-
ness connector for the seat belt switch and a good
ground. There should be no continuity. If OK, go to
Step 4. If not OK, repair the shorted seat belt switch
sense circuit between the seat belt switch and the
instrument cluster as required.
(4) Check for continuity between the seat belt
switch sense circuit cavities of the seat wire harness
connector for the seat belt switch and the instrument
panel wire harness connector (Connector C2) for the
instrument cluster. There should be continuity. If
OK, test and replace the faulty instrument cluster as
required. (Refer to 8 - ELECTRICAL/INSTRUMENT
CLUSTER - DIAGNOSIS AND TESTING). If not OK,
repair the open seat belt switch sense circuit between
the seat belt switch and the instrument cluster as
required.
SEAT BELT TENSIONER
DESCRIPTION
ANY STEERING
ers supplement the driver and passenger airbags for
all versions of this model (Fig. 48). The seat belt ten-
sioner is integral to the front outboard seat belt and
retractor units, which are secured to the inner B-pil-
lar on the right and left sides of the vehicle. The
retractor is concealed beneath the molded plastic
inner B-pillar trim. The seat belt tensioner consists
primarily of a die cast aluminum tensioner housing
or chamber, a mechanical clutch unit, a tape-like
metal strip, a pair of cutters, a pyrotechnically acti-
vated gas generator, and a short pigtail wire. All of
these components are located on one side of the
retractor spool on the outside of the retractor hous-
ing. The seat belt tensioners are controlled by the
Airbag Control Module (ACM) and are connected to
the vehicle electrical system through a dedicated
take out of the body wire harness by a keyed and
latching molded plastic connector insulator to ensure
a secure connection.
faulty or damaged, the entire outboard front seat belt
and retractor unit must be replaced. If the front air-
bags have been deployed, the seat belt tensioners
have also been deployed. The seat belt tensioners are
not intended for reuse and must be replaced follow-
ing any front airbag deployment. A locked retractor
that will not allow the seat belt webbing to be
Fig. 48 Seat Belt Tensioner
1 - TENSIONER HOUSING OR CHAMBER
2 - GAS GENERATOR
3 - TENSIONER PIGTAIL WIRE
4 - SPOOL
5 - TENSION REDUCER (DRIVER SIDE ON STANDARD CAB
ONLY)
6 - REDUCER CONNECTOR RECEPTACLE
7 - RETRACTOR LOCKING MECHANISM COVER
Front outboard seating position seat belt tension-
The seat belt tensioners cannot be repaired and, if
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