Chevrolet 70 1969 Series, Shop Manual

Page: 38 / 913

C A B A N D B O D Y
M OUNTINGS 1-11
rotates whenever the wiper motor is running. Pro­
gramming is accomplished electrically and mech­
anically through use of a pump solenoid circuit
and ratchet wheel arrangement.
O P E R A T IO N
Conventional Cab Models (Single Wiper Motor)
Pushing in on the wiper switch knob causes the
washer to activate and also causes wipers to ac­
tivate in " L O W ” speed. If operator wishes high
speed wiper action he must manually switch to
"H IG H " speed. At the end of washer cycle, washer
will automatically shut off; wiper must be shut off
manually, regardless of high or low speed.
T ilt Cab Models (Two Wiper Motors)
Pushing in switch knob of left-hand wiper
switch causes washer to activate, and also causes
left-hand wiper to activate in " L O W " speed. If
operator wishes "H IG H " speed and/or right-hand
wiper action also, he must manually control both.
At the end of washer cycle, washer will automatic­
ally shut off; wiper(s) must be shut off manually
regardless of speed (both left- and right-hand).
P U M P R E M O V A L (Figs. 13 and 14)
1. Disconnect water hoses to washer pump
making certain they are properly marked to as­
sure correct installation.
2.
Disconnect electric wiring from washer
terminals.
3. Remove washer pump attaching screws, then
lift pump off wiper motor.
P U M P
IN S T A L L A T IO N (Figs. 13 and
14)
1. Place washer pump in position on wiper
motor making sure lever arm pin properly engages
four-lobe cam.
2. Secure pump to motor with two mounting
screws.
3. Reconnect electric wiring.
4. Reconnect water hoses.
T R O U B L E S H O O T IN G W A S H E R P U M P
On-Vehicle Check (Fig. 15)
1. If washer pumps continuously when wiper is
on, disconnect wiring from washer pump.
a. If pump shuts off, trouble is located in wir­
ing harness or dash switch.
b. If pump fails to shut off in Step a, remove
pump assembly from vehicle for further checking.
2. Check the following items if pump is in­
operative:
a. Reservoir contains water solution.
b. Hoses are not damaged and hose connec­
tions are tight,
c. Screen at end of jar hose is not plugged.
d. Electrical connections to washer pump and
dash switch are secure,
e. Nozzles are not plugged.
3. If all items in Step 2 check out, start wiper
motor only, then push washer button and listen for
"click” as washer solenoid pulls in. If no "click”
is heard, check for 12 volts at terminal No. 2 (fig.
15). No voltage indicates defective wiring. If
•'‘'click'''’ is heard, proceed to Step 5.
4. If correct voltage was found in Step No. 3,
connect a jumper wire from washer terminal No.
1 to ground (fig, 15) and operate wiper. If washer
relay “ click” i . and pump functions cor­
rectly, a defect] l switch or an open circuit
between washer nd dash switch is indicated
- "N o Click'-’ inc an open pump solenoid.
5. If relay is heard in Step 3, listen
for the soft, clicking as the pump ratchet wheel is
rotated,
a. If soft clicking is not heard, the pump mech­
anism is faulty and should be removed from the
wiper motor and checked.
b. If soft clicking is heard but no pumping ac­
tion occurs, replace the valve assembly and re­
check pump.
CAM FO ILO
LO W ER PIN
‘
f o u r
LOBE CAM
t
5530
F ig u re
14—Separating W asher Pum p From Motor
"H a 'K O t.i'i -.ERICS 70-80 HEAVY DUTY TRUCK SHOP M A N U A L