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Mirrors
Power Mirrors Without A45 Block Diagram
3270441
Power Mirror System Controls
The outside mirror switch incorporates a mirror select
switch and a 4 position mirror direction switch.
The mirror select switch allows the driver to select the
mirror to be moved by turning the switch to L position
enabling the left outside mirror or turning the switch to
R position enabling the right outside mirror.
The mirror direction switch is a 4 position switch that
allows the operator to move the selected mirror up,
down, left or right.
Power Mirror System Operation
The outside mirror switch receives power through the
battery positive voltage circuit from the underhood fuse
block. The outside mirror switch also receives a
constant ground.
The 4 positions of the direction switch have multiple
switch contacts. When not in use, the directional
contacts are isolated from any circuit. Each of the
contacts are connected to opposing sides of the
appropriate mirror motors through the selector switch.
The selector switch interrupts or completes these
circuits depending on the position of the selector
switch, L or R.
If the mirror select switch is placed in the L position
and the up switch is pressed, battery voltage will be
supplied to the driver outside mirror vertical motor
through the driver mirror motor up control circuit and
return to the mirror switch through the driver mirror
motor left/down control circuit, then to ground and the
mirror will move up. If the down switch is pressed, the
driver mirror motor left/down control circuit supplies
battery voltage and the driver mirror motor up control
circuit completes the path to the mirror switch, then to
ground and the mirror will move down.
The remainder of the mirror functions operate in the
same manner as described above. Placing the mirror
control switch in opposing positions, left/right or up/
down, will reverse the voltage polarity to the mirror
motor, utilizing the same circuits and the mirror will
move accordingly.
Heated Mirrors
The heated mirrors are controlled through the rear
defog relay. Whenever the rear window defogger is
turned ON, battery voltage is supplied to the mirror
heater elements through the left and right mirror heater
element control circuits.
2021 - Silverado 4500HD, 5500HD, and 6500HD Electrical Body Builder Manual
