Wiper/washer System - Front Buick Century V

DESCRIPTION

The windshield wiper/washer system uses a depressed park wiper motor with a remote windshield washer pump mounted on washer reservoir. The system is designed to deliver pulse timing and demand wash functions electronically. Depending on control switch design and whether an integral electronic printed circuit board is used in the wiper cover, the system can function as either a pulse or standard wiper/washer system.

OPERATION

Logic circuits on pulse wiper system's printed circuit board create the timing and washer commands. Whenever the WASH switch is pressed for less than one second, washer solvent sprays onto the windshield for approximately 2.5 seconds, and wiper cycle is activated for approximately 6 seconds.

If WASH switch is held for more than one second, a demand wash will be performed for as long as switch is held. This wash cycle is followed by the 6-second wiper cycle. When the control switch is in LO or HI position, the motor runs at set speed.

In PULSE mode, the wiper motor operates intermittently. The delay can be varied by adjusting the switch back and forth within the delay mode. An instant wipe is caused by placing the switch in the MIST position (if equipped). The wiping action continues until the switch is released.

WIPER ARM

Note. Check wiper arm wiping pattern on wet windshield.

1. Remove right side wiper arm and blade assembly. Loosen drive crank arm adjuster nuts. (Scheme 1) Rotate left side arm and blade assembly to position slightly below blade stop. Tighten adjuster nuts to 62 INCH lbs. (7 N.m).
2. Position right side arm and blade assembly slightly below blade stop. Install right side assembly onto drive shaft. Lift right and left assemblies over stops.

Scheme 1

TESTING

Note. Unless otherwise specified, make all measurements with a digital volt-ohmmeter having an input impedance of 10 megohms.

Before performing following tests, ensure wiper motor module mounting hardware is secure, washer hoses are in good condition, and wiring and fuses are okay.

SYSTEM TESTING

Refer to WIPER SYMPTOMS table, then go to appropriate test.

WIPER SYMPTOMS

Scheme 2

1. Turn ignition off. Unplug connector from wiper/washer switch. Turn ignition on. Using a test light, check for battery voltage at harness connector terminal E5 (Yellow wire). If battery voltage exists, go to next step. If battery voltage does not exist, check for open circuit in Yellow wire from fuse panel.
2. Unplug 3-pin connector from wiper motor. Connect test light between battery voltage and harness connector terminal "C" (Black wire). (Scheme 2) If test light glows, go to next step. If test light does not glow, repair Black wire between 3-pin connector and ground.
3. Reconnect wiring to wiper/washer switch. Unplug 6-pin connector from wiper motor. Using test light, check for battery voltage at 6-pin connector terminal "C" (Dark Green wire). If battery voltage exists, go to next step. If battery voltage does not exist, check for open circuit in Dark Green wire between switch and wiper motor. If wire is okay, replace switch.
4. Set wiper switch to LO position. Using test light, check for battery voltage at 6-pin connector terminal "B" (Gray wire). If battery voltage exists, go to next step. If battery voltage does not exist, check for open in Gray wire between switch and wiper motor. If wire is okay, replace switch.
5. Check for continuity between terminal "A" (Yellow wire) on 6-pin connector and terminal "B" (Yellow wire) on 3-pin connector. If continuity exists, go to next step. If continuity does not exist, repair open in Yellow wire.
6. Check for poor connections at wiper motor. If connections are okay, replace wiper motor.

Test 2, Wipers Run At High Speed Only

1. Unplug 6-pin wiper motor connector. Turn ignition on. Set wiper switch to LO position. Using test light, check for battery voltage at connector terminal "C" (Dark Green wire). (Scheme 2) If battery voltage exists, go to next step. If battery voltage does not exist, check for open in Dark Green wire between wiper motor and switch. If wire is okay, replace switch.
2. Turn ignition off. Check for continuity between terminal "A" (Yellow wire) on 6-pin connector and terminal "B" (Yellow wire) on 3-pin connector. If continuity exists, go to next step. If continuity does not exist, repair open in Yellow wire.
3. Check for poor connections at wiper motor. If connections are okay, replace wiper motor cover.

Test 3, Wipers Run At Low Speed Only

1. Unplug 6-pin wiper motor connector. Turn ignition on. Set wiper switch to HI position. Using test light, check for battery voltage at connector terminal "A" (Purple wire). (Scheme 2) If battery voltage exists, go to next step. If battery voltage does not exist, check for open in Purple wire between wiper motor and switch. If wire is okay, replace switch.
2. Check for poor connections at wiper motor. If connections are okay, replace wiper motor.

Test 4, Wipers Run Intermittently

1. Ensure windshield is dry. Connect ammeter in place of wiper fuse. Turn ignition on. Set wiper switch to LO position. Measure current with wipers operating (current will fluctuate). If lowest current is not less than 3.5 amps, go to next step. If lowest current is less than 3.5 amps, replace wiper motor.
2. If lowest current is greater than 6.5 amps, go to next step. If lowest current is not greater than 6.5 amps, circuit is okay.
3. Replace wiper blades. Repeat steps 1) and 2). If lowest current is greater than 6.5 amps, go to next step. If lowest current is not greater than 6.5 amps, circuit is okay.
4. Disconnect wiper linkage from wiper motor. Repeat steps 1) and 2). If lowest current is greater than 6.5 amps, replace wiper motor. If lowest current is not greater than 6.5 amps, repair binding linkage as necessary.

Test 5, Wipers Do Not Turn Off

1. Unplug 6-pin wiper motor connector. Turn ignition on. Set wiper switch to OFF position. Measure voltage at connector terminal "B" (Gray wire). (Scheme 2) If voltage is zero volts, go to next step. If voltage exists, check for short to voltage on Gray wire. If wire is okay, replace wiper switch.
2. Unplug 3-pin wiper motor connector. Measure voltage at 3-pin connector terminal "A" (Purple wire). If voltage is zero volts, repair short to voltage in Yellow wire between 3-pin and 6-pin connectors. If voltage exists, check for short to voltage on Purple wire between 3-pin connector and switch. If wire is okay, replace wiper/washer switch.

Test 6, Wipers Do Not Park Properly

1. Turn ignition on. Set wiper switch to LO position. If wipers operate at low speed, go to next step. If wipers do not operate at low speed, go to TEST 2, WIPERS RUN AT HIGH SPEED ONLY.
2. Inspect motor. Replace motor if it has a bent drive pawl or excessive end play in output shaft. If motor is okay, replace park switch.

Test 7, Pulse Delay Incorrect

1. Turn ignition off. Unplug wiper/washer switch connector. Set switch to DELAY position. Connect ohmmeter between switch terminals E5 (White wire on mating connector) and E9 (Pink wire on mating connector). Operate wiper switch through entire delay range. If resistance varies between approximately 24,000 ohms and 1.2 megohms, go to next step. If resistance does not vary as specified, replace wiper/washer switch.
2. Measure resistance between switch terminals E5 (White wire on mating connector) and E6 (Gray wire on mating connector). If resistance is less than 3 ohms, go to next step. If resistance is not less than 3 ohms, replace wiper/washer switch.
3. Inspect Gray and Pink wires between switch and motor for open circuit or poor connection. Repair as necessary. If wires are okay, remove wiper motor cover. If park switch terminals touch pads on circuit board, replace wiper motor cover. If park switch terminals do not touch pads on circuit board, replace park switch spring contacts.

Test 8, Washer Does Not Operate

1. Unplug washer pump connector. Connect test light between harness connector terminals. Turn ignition on. Operate washer switch. If test light does not come on, go to next step. If test light comes on, check for poor connections at pump. If connections are okay, replace pump.
2. Connect test light to pump harness connector terminal "A" (Red wire). Operate washer switch. If test light does not come on, go to next step. If test light comes on, repair Black wire between pump harness connector and ground.
3. Using test light, backprobe wiper motor 6-pin connector terminal "D" (Red wire). (Scheme 2) Operate washer switch. If test light does not come on, go to next step. If test light comes on, check for open in Red wire between wiper motor and washer pump.
4. Turn ignition on. Backprobe wiper/washer switch connector terminal E9 (Pink wire). Operate washer switch. If voltage is zero volts, replace wiper/washer switch. If voltage exists, check for open circuit in Pink wire between switch and wiper motor or poor connections. If wire is okay, replace wiper motor cover.

Test 9, Washer Does Not Shut Off

1. Turn ignition on. Set wiper/washer switch to LO position. Unplug wiper motor 6-pin connector. Connect test light between connector terminal "F" (Pink wire) and wiper motor case. (Scheme 2)
2. Operate washer switch. If test light glows when washer switch is released, replace wiper/washer switch. If test light does not glow when washer switch is released, replace wiper motor cover.

REMOVAL & INSTALLATION

1. Disconnect washer hoses. Remove wiper arms. Remove air inlet screen. Disengage wiper arm drive link from crank arm. Unplug electrical connectors.
2. Remove any interfering components. Remove wiper motor mounting bolts. Carefully guide crank arm through access hole. Remove wiper motor. Remove crank arm from motor. To install, reverse removal procedure. Tighten mounting bolts to 80 INCH lbs. (9 N.m).

Remove wiper motor from vehicle (if necessary). See WIPER MOTOR R & I . Unplug electrical connectors. Remove wiper motor cover screws. Remove cover. To install, reverse removal procedure. Tighten screws to 18 INCH lbs. (2 N.m).

Remove wiper motor cover. See WIPER MOTOR COVER. If wiper motor is in parked position, operate motor to remove lock pawl from relay slot. (Scheme 3)and (Scheme 4). Remove park switch. To install, reverse removal procedure.

Scheme 3

Scheme 4

Drain washer reservoir. Unplug washer motor electrical connector. Remove necessary reservoir attaching hardware. Remove reservoir. Remove motor retaining screws and motor. To install, reverse removal procedure.

Scheme 5

Scheme 6

1. With wiper motor removed from vehicle, remove crank arm retaining nut. Disconnect crank arm. Remove rubber seal cap and thrust collar or retaining ring. (Scheme 5)and (Scheme 6).
2. Remove shims, shield, and spacer washer. Remove park switch. Remove large gear, inner spacer washer, intermediate gear retainer, and intermediate gear. When removing large gear, ensure latch arm is out of way. (Scheme 3) Disassemble drive plate and shaft assembly.

Reassembly

1. Install intermediate gear and NEW intermediate gear retainer. Install inner spacer washer onto large gear tube. Install large gear, spacer washer, and shield. Use shims to obtain.001-.010" (.03-.26 mm) end play. NOTE: Move drive and lock pawls as required to fit respective pins into gear pockets. Ensure drive plate is firmly against gear.
2. Install retaining ring (in place of thrust collar on original motor). Install rubber seal cap. Install crank arm (check crank arm for proper position when it is in parked position). (Scheme 5) Tighten crank arm nut to 31 ft. lbs. (42 N.m).

Wiper/Washer System Wiring Diagram - Standard). Scheme 7

Wiper/Washer System Wiring Diagram - Pulse). Scheme 8

See also:
• COMPUTER RELEARN PROCEDURES
• WIPER SYMPTOMS