Jeep 1997 Grand Cherokee Service Manual page 594

8T - 6 POWER MIRROR SYSTEMS
GENERAL INFORMATION
INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . 6
DESCRIPTION AND OPERATION
AUTOMATIC DAY/NIGHT MIRROR . . . . . . . . . . . 6
GENERAL INFORMATION
INTRODUCTION
An automatic dimming inside day/night rear view
mirror and an automatic dimming driver side outside
rear view mirror are available factory-installed
options on this model. Following is a general descrip-
tion of this optional equipment. Refer to 8W-44 -
Interior Lighting and 8W-62 - Power Mirrors in
Group 8W - Wiring Diagrams for complete circuit
descriptions and diagrams.
NOTE: This group covers both Left-Hand Drive
(LHD) and Right-Hand Drive (RHD) versions of this
model. Whenever required and feasible, the RHD
versions of affected vehicle components have been
constructed as mirror-image of the LHD versions.
While most of the illustrations used in this group
represent only the LHD version, the diagnostic and
service procedures outlined can generally be
applied to either version. Exceptions to this rule
have been clearly identified as LHD or RHD, if a
special illustration or procedure is required.
DESCRIPTION AND OPERATION
AUTOMATIC DAY/NIGHT MIRROR
The automatic day/night mirror is able to automat-
ically change its reflectance. A thin layer of electro-
chromic material between two pieces of conductive
glass make up the face of the mirror. Two photocell
sensors are used to monitor light levels and adjust
the reflectance of the mirror to reduce the glare of
headlamps approaching the vehicle from the rear.
The ambient photocell sensor faces forward, to
detect the outside light levels. The headlamp sensor
faces rearward, to detect the light level received at
the rear window side of the mirror. When the differ-
ence between the two light levels becomes too great
(the light level received at the rear of the mirror is
much higher than at the front of the mirror), the
mirror begins to darken.
AUTOMATIC DAY/NIGHT MIRROR
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INDEX
DIAGNOSIS AND TESTING
AUTOMATIC DAY/NIGHT MIRROR . . . . . . . . . . . 6
REMOVAL AND INSTALLATION
AUTOMATIC DAY/NIGHT MIRROR . . . . . . . . . . . 7
The mirror switch allows the driver a manual con-
trol of whether the automatic dimming feature is
operational. When On is selected, the mirror switch
is lighted by an integral Light-Emitting Diode (LED).
The automatic dimming feature will only operate
when the ignition switch is in the On position. The
mirror also senses the backup lamp circuit, and dis-
ables the self-dimming feature whenever the trans-
mission gear selector is in the Reverse position.
On models with an optional electrochromic driver
side outside rear view mirror, the signal to control
the dimming of that mirror is generated by the auto-
matic day/night inside rear view mirror circuitry.
That signal is then delivered to the driver side out-
side rear view mirror on a hard-wired circuit.
The automatic
repaired. If faulty or damaged, the entire inside rear
view mirror assembly must be replaced.
DIAGNOSIS AND TESTING
AUTOMATIC DAY/NIGHT MIRROR
For circuit descriptions and diagrams, refer to
8W-44 - Interior Lighting or 8W-62 Power Mirrors in
Group 8W - Wiring Diagrams.
(1) Check the fuse in the junction block. If OK, go
to Step 2. If not OK, replace the faulty fuse.
(2) Turn the ignition switch to the On position.
Check for battery voltage at the fuse in the junction
block. If OK, go to Step 3. If not OK, repair the open
circuit to the ignition switch as required.
(3) Unplug the wire harness connector from the
mirror (Fig. 1). Check for battery voltage at the fused
ignition switch output circuit cavity of the mirror
wire harness connector. If OK, go to Step 4. If not
OK, repair the open circuit to the junction block as
required.
(4) Turn the ignition switch to the Off position.
Check for continuity between the ground circuit cav-
ity of the mirror wire harness connector and a good
ground. There should be continuity. If OK, go to Step
5. If not OK, repair the circuit to ground as required.
day/night mirror cannot
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