Dodge RAM TRUCK 1500 1995 Service Manual page 191

BR
POWER BRAKE BOOSTER—BRAKE PEDAL—BRAKELIGHT SWITCH 5-19
BRAKELIGHT SWITCH TEST AND DIAGNOSIS
Brakelight switch operation can be tested with an
ohmmeter. The ohmmeter is used to check continuity
between the pin terminals at different plunger posi­
tions (Fig. 9).
T h e s w i t c h w i r e harness must be discon­
n e c t e d "before testing s w i t c h continuity.
Switch Circuit Identification
• Switch terminals 1 and 2 are for the brake sensor
circuit
• Switch terminals 5 and 6 are for the brakelight
circuit
• Switch terminals 3 and 4 are for the speed control
circuit
TERMINAL
PINS
J9405-88
Fig. 9 Brakelight Switch Terminal Identification And
Plunger Test Position
Switch Continuity Test Procedure
(1) Check continuity between terminal pins 5 and
6 as follows:
(a) Pull plunger all the way out to fully extended
position.
(b) Attach test leads to pins 5 and 6 and note
ohmmeter reading.
(c) If continuity exists, proceed to next test. Re­
place switch if meter indicates lack of continuity
(shorted or open).
(2) Check continuity between terminal pins 1 and
2 and pins 3 and 4 as follows:
(a) Push switch plunger inward to fully retracted
position.
(b) Attach test leads to pins 1 and 2 and note
ohmmeter reading.
(c) If continuity exists, switch is OK. Replace
switch if meter indicates lack of continuity (switch
is shorted/open).
BRAKELIGHT SWITCH ADJUSTMENT AND
INSTALLATION
(1) Preset switch plunger as follows:
(a) Pull switch plunger all the way out to fully
extended position.
(b) Push switch plunger inward 4 detent posi­
tions (or clicks). This is required preset position for
switch installation. Plunger will extend approxi­
mately 14 mm (0.55 in.) out of housing at this set­
ting.
(2) Connect harness wires to switch (Fig. 8).
(3) Press and hold brake pedal down.
(4) Install switch. Align tab on switch with notch
in switch bracket (Fig. 10). Then insert switch in
bracket and turn it clockwise about 30° to lock it in
place.
(5) Release brake pedal. Then lightly pull pedal
fully rearward. Pedal will adjust switch plunger to
correct position as pedal is moved to rear.
CAUTION: Do not use excessive force to move the
pedal rearward for switch adjustment. Excessive
force will damage the switch.
Fig. 10 Brakelight Switch Installation
BRAKE PEDAL REiOWAL
(1) Remove knee bolster for access to brakelight
switch and pedal (Fig. 5).
(2) Remove brakelight switch (Fig. 8).
(3) Remove switches from tabs on brakelight
switch bracket.
(4) Remove brakelight switch bracket (Fig. 11).
Bracket is attached to pedal mounting bracket with
two screws.
(5) Remove clip and washer attaching booster push
rod to brake pedal (Fig. 6). Then slide push rod off
pedal.
(6) Remove E-clip from passenger side of pedal
shaft (Fig. 12). Use flat blade screwdriver to pry clip
out of shaft groove.
(7) Push shaft toward driver side of bracket just
enough to expose opposite E-clip. Then remove E-Clip
with flat blade screwdriver.
(8) Push pedal shaft back and out of passenger
side of bracket (Fig. 12).