Pontiac Fiero 1988 Service Manual page 1099

WIPER/WASHER: P U L S E I T i M
(Continued from previous page)
Switch in MIST, LO, HI, or WASHER position,
voltage is applied to the Solid State Control
through the GRY (91) wire. This voltage signals
the Solid State Control to ground the coil of the
Park/Run Relay. With the Park/Run Relay ener-
gized, voltage is applied through the contacts of
the relay to the Wiper Motor for low speed
operation.
PARK
When the Wiper/Washer switch is turned to
OFF, the Park/Run Switch provides the ground
for the Park/Run Relay. The relay contacts
remain closed and the Wiper Motor continues
to run in low speed until the Wipers reach
PARK position. At this time, a cam on the large
gear mechanically opens the Park/Run Switch,
which removes ground from the Park/Run
Relay. This de-energizes the relay, and the relay
contacts open. Battery voltage is removed from
the Wiper Motor, shutting off the Wipers.
HIGH SPEED
For high speed wiping, battery voltage from
the Wiper/Washer Switch is directly applied to
the HI speed terminal of the Wiper Motor
through the PPL (92) wire. When the Wiper/
Washer Switch is turned to OFF, the Wipers
park at the low speed under control of the Park/
Run Switch.
PULSE
With the Wiper/Washer Switch in PULSE,
voltage is applied to the Solid State Pulse/Speed/
Wash Control through the GRY (91) wire. This
voltage signals the Solid State Pulse/Speed/Wash
Control to momentarily ground the coil of the
| Park/Run Relay. With the Park/Run Relay ener-
gized, voltage is applied through the contacts of
the relay to the Wiper Motor.
After the Wipers have started, the Park/Run
Switch supplies battery voltage until the Wipers
return to PARK position. The Wipers remain
parked until the Solid State Pulse/Speed/Wash
Control again grounds the Park/Run Relay coil.
The length of the delay time between strokes
is controlled by the variable pulse delay resistor.
From the low position, the delay cycles are 18,
10, 6, 3, and 1.25 seconds.
MIST
When the control is moved to MIST and re-
leased, the Wipers make one sweep at low speed
and return to park. The circuit operation is the
same as that of LO.
WASHER
When the Washer Switch is depressed, this
signals the Solid State Control to apply battery
voltage to the Washer Pump (ORN to PNK
wires) and also to start the wiper cycle. The
Washer continues as long as its switch is held
down. The Solid State Control keeps the Wipers
on for about six seconds after the Washer goes
off. If the Washer is switched on during pulse
operation, the cycle of wash with six seconds of
low speed wipes is completed before the system
returns to delayed pulse wiping.