Dodge ZB 2005 Service Manual page 299

8L - 4 LAMPS
BRAKE LAMP SWITCH
DESCRIPTION
The brake lamp switch is located under the instru-
ment panel, at the brake pedal arm. It has three
internal switches controlling various functions of the
vehicle. It's main function is to control operation of
the vehicle's brake lamps.
CAUTION: The brake lamp switch can only be
adjusted once. That is during initial installation of
the switch. If the switch is not adjusted properly or
has been removed for some service, a new switch
must be installed and adjusted.
OPERATION
When the brake pedal is pressed, the plunger on
the outside of the brake lamp switch extends out-
ward. This action opens or closes the contacts of the
three switches inside the brake lamp switch.
With the brake pedal pressed down (plunger
extended), the switch for terminals 1 and 2 is closed
completing the circuit. The switch for terminals 3
and 4 is open and so is the switch for terminals 5
and 6.
When the brake pedal is released (plunger pushed
in), the three switches assume the opposite positions.
The switch for terminals 1 and 2 is now open while
the other two switches are now closed, completing
their circuits.
A lever on the back of the switch is used to set the
switch into the "adjusted" position. A non-adjusted
switch will have the lever set to the diagonal position
in relation to the switch housing. The plunger can be
moved in and out, but the states of the internal
switches will not change.
CAUTION: Never move the adjustment lever of the
new brake lamp switch without it being properly
installed in the vehicle first. Such action will render
the switch unusable and the switch must be dis-
carded.
Once installed in the vehicle as described in the
brake lamp switch installation procedure (Refer to 8 -
ELECTRICAL/LAMPS/LIGHTING
BRAKE LAMP SWITCH - INSTALLATION), the new
switch's adjustment lever is rotated to the adjusted
position as indicated. This action locks the plunger to
the internal switches. Once in this position the
switch is permanently adjusted (or locked) and
cannot be readjusted or released even if the
lever is moved back.
DIAGNOSIS AND TESTING - BRAKE LAMP
SWITCH
NOTE: Before proceeding with this diagnostic test,
verify the adjustment lever on the back of the
switch is in the adjusted position. If the lever is in
the non-adjusted (diagonal) position it may have
never been adjusted (Refer to 8 - ELECTRICAL/
LAMPS/LIGHTING
SWITCH - OPERATION). For adjustment, (Refer to 8
-
BRAKE LAMP SWITCH - INSTALLATION)
If the electrical circuit has been tested and the
brake lamp switch is suspected of being faulty, it can
be tested using the following method.
(1) Remove the switch from the vehicle. (Refer to 8
- ELECTRICAL/LAMPS/LIGHTING - EXTERIOR/
BRAKE LAMP SWITCH - REMOVAL)
(2) With the switch in the released position
(plunger extended), use an ohmmeter to test each of
the three internal switches as shown (Fig. 1). You
should achieve the results as listed in the figure.
(3) Gently push the plunger on the brake lamp
switch in until it stops.
(4) With the switch in this depressed position
(plunger pushed in), use an ohmmeter to test each of
- EXTERIOR/
the three internal switches as shown (Fig. 2). You
should achieve the results as listed in the figure.
If you do not achieve the results as listed in both
figures, the switch is faulty and must be replaced.
Refer to Removal And Installation in this section.
If the switch is found to be operating properly, it
may be misadjusted. Do not reinstall the switch,
replace it. (Refer to 8 - ELECTRICAL/LAMPS/
LIGHTING - EXTERIOR/BRAKE LAMP SWITCH -
INSTALLATION)
- EXTERIOR/BRAKE
ELECTRICAL/LAMPS/LIGHTING
Fig. 1 SWITCH TEST - RELEASED POSITION
ZB
LAMP
- EXTERIOR/