Pontiac Fiero 1988 Service Manual page 1145

POWER R E M O T E MIRRORS
(Continued from previous page)
A: O U T S I D E MIRROR SWITCH POWER
AND G R O U N D T E S T
Measure:
VOLTAGE
At: OUTSIDE MIRROR SWITCH CONNECTOR
(Disconnected)
Measure
Between
Correct
Voltage
For
Diagnosis
A (ORN) &
Ground
Battery Seel
A (ORN) & B
(BLK)
Battery See
2
• If all voltages are correct, replace Outside
Mirror Switch.
1. Check/repair ORN (40) wire.
2. Check/repair BLK (150) wire.
B: LH OUTSIDE MIRROR SWITCH TEST
Measure: VOLTAGE
At: OUTSIDE
MIRROR
SWITCH
CONNECTOR (Connected)
Conditions:
© Mirror
Select Switch: LH
• Mirror
Control
Switch:
Hold
in UP &
DOWN
Measure
Between
Correct
Voltage
For Diagnosis
C(YEL)&E
(LTGRN/
BLK)
Battery
Seel
Continued from previous column)
© Hold Mirror Control Switch in LEFT &
RIGHT
D (LT BLU) &
F (WHT/BLK)
Battery
Seel
© If all voltages are correct, replace the LH
Outside Mirror Drive Unit after checking
connector C310, YEL (88), LT GRN (89),
WHT (81) and LT BLU (82) wires.
1. Replace the Outside Mirror Switch.
C: RH OUTSIDE MIRROR SWITCH TEST
(Continued in next column)
Measure: VOLTAGE
A t : OUTSIDE MIRROR
SWITCH
CONNECTOR (Connected)
Conditions:
* Mirror Select Switch: RH
« Mirror
Control
S w i t c h :
Hold in
UP and
Measure
Between
C (YEL) & G
(LTGRN)
Correct
Voltage
Battery
For Diagnoses
Seel
• Hold Mirror Control Switch LEFT &
RIGHT
D (LT BLU) &
H
(WHT)
Battery Seel
If all voltages are correct, replace the RH
Outside Mirror Drive Unit after checking
connector C311, YEL (88), LT GRN (89),
WHT (81) and LT BLU (82) wires.
Replace Outside Mirror Switch.
CIRCUIT OPERATION
Each Outside Mirror has two reversible
motors, one motor adjusts the mirror view up
and down, the other motor adjusts the mirror
view right and left. The driver operates four
switches that control the polarity of the voltage
to the motors. The Mirror Select Switch directs
these control voltages to either the RH or LH
Outside Mirror.
With the switches in the positions shown in
the schematic, the LH Outside Mirror is moved.
When the Up-Down Switch is moved UP, bat-
tery voltage from the ORN wire is applied to the
YEL wire and the Up-Down Motor in each Out-
side Mirror. The LH Outside Mirror Up-Down
Motor has a path to ground through the LT
GRN/BLK wire, the UP contacts of the Up-
Down Switches and the BLK wire. The LH
motor runs and turns the mirror up.
If the Mirror Control Switch is pushed to the
DOWN position, the same motor receives
voltage. Now the polarity is reversed, with the
YEL wire grounded. The motor runs in the
opposite direction.
The LH Outside Mirror Left-Right Motor
operates in a similar manner when the joy stick
moves the Left-Right Switch to LEFT. The
WHT/BLK wire gets battery voltage and the
LT BLU wire is grounded through the Left-
Right Switch.
The RH Outside Mirror works the same way
as the LH Outside Mirror when the Mirror
Select is moved to the RH position and the joy
stick is operated.