Chrysler RAM TRUCK 2500 1994 Service Manual page 510

POWER SEATS
C O N T E N T S
p a g e
DIAGNOSIS 1
GENERAL 1
POWER SEAT MOTOR REPLACEMENT 2
page
POWER SEAT SWITCH REPLACEMENT 2
SWITCH TESTING 2
GENERAL
The power seat can be adjusted i n 6 different direc­
tions (Fig. 1). The control switch is on the lower out­
board side of the seat.
The front lever on the switch raises or lowers the
front of the seat cushion; the center lever raises or
lowers the complete seat by moving the switch up or
down. I t also moves i t forward or rearward by mov­
ing the switch forward or rearward. The rear lever
raises or lowers the rear of the seat cushion.
1. SEAT UP A N D D O W N
2. SEAT FORWARD A N D REARWARD
3. SEAT TILT (FRONT UP A N D D O W N )
4. SEAT TILT (REAR UP A N D D O W N )
J938R-4
Fig. 1 Power Seat Switch
There are 3 reversible motors that operate the
power seat. The front and rear of the seat cushion
are operated by different motors. They can be raised
or lowered independently of each other. Moving the
center position seat switch to either the UP or
DOWN position, runs both the front and rear motors
at the same time.
The forward-rearward motor is operated by the
center position seat switch. When the switch is held
in the FORWARD position, battery voltage is applied
through the switch contacts to the forward-rearward
motor. The motor is grounded and the motor runs to
drive the seat forward until the switch is released.
With the switch i n the REAR position, the polarity
is reversed and causes the motor to run i n the oppo­
site direction and drive the seat backward.
The front motor works i n a similar way when the
front height switch is operated.
To raise the entire seat, the center position seat
switch is held i n the UP position. This applies bat­
tery voltage to both the front and rear motors. Both
motors run to drive the entire seat up. A similar ac­
tion occurs to move the entire seat down.
Each motor contains a self-resetting circuit breaker
to protect i t from overload. Consecutive or frequent
resetting must not be allowed to continue. Make nec­
essary repairs.
DIAGNOSIS
Refer to Group 8W-Wiring Diagrams for a complete
circuit diagram.
Before any testing is attempted the battery should
be fully charged and all connections and pins cleaned
and tightened to insure proper continuity and
grounds.
With the dome lamp on, apply switch i n direction
of the failure. I f the dome lamp dims, the seat may
be jamming. Check for binding. I f the dome lamp
does not dim, then proceed with the following electri­
cal tests.
S E A T MOTOR
ASSEMBLY
• Position seat switch to move all 3 seat motors. The
seat should move i n all directions. I f not, go to No
Seat Motors Operate. I f one or more motors operate,
refer to Switch Testing.
Test seat switch. I f OK, replace defective motor.
NO SEAT MOTORS OPERATE
30 amp circuit breaker #2 (fuseblock module)
installed.
• Probe circuit breaker, on fuseblock module. I f bat­
tery voltage is present, replace circuit breaker.