Washer Pump Current Draw

Tools Required:

• Rotunda Digital Volt Ohmmeter 014-00407
• Rotunda Starting and Charging Tester 078-00005

Attach leads of the volt-amp tester, such as Rotunda Starting and Charging Tester 078-00005 or Rotunda Digital Volt-Ohmmeter 014-00407 or equivalent. The current draw should not exceed four amps, or indicate less than two amps, while washer pump motor is pumping fluid.

Refer to diagnosis charts for windshield washer checks.  

PINPOINT TEST A: WIPERS WILL NOT PARK

A1 CHECK WIPER MOTOR  

• Stop wipers with ignition switch so that they are not in PARK position.

• Unplug wiper motor and connect jumpers to motor connector as shown.
  
  
  
  

CHECK for:

• Open connection.
• Malfunctioning governor.
• Open wire circuit 58 (W) or 28 (BK/PK). SERVICE or REPLACE as required.

Wipers do not park
REPLACE wiper motor.

 

PINPOINT TEST B: WINDSHIELD WASHER DOES NOT OPERATE

 

B1 CHECK FLUID LEVEL

• Check level of fluid in reservoir.

• Is fluid level good?

Yes
GO to B2.

No
FILL reservoir.

 

B2 ACTIVATE WASHER SWITCH

• Activate washer switch.

• Check motor for operation.

Motor inoperative
GO to B5.

Motor operates, but will not squirt fluid
GO to B3.

 

B3 INSPECT HOSE AND NOZZLE

• Visually inspect washer hose and nozzle for blockage or hose kinks.

• Is hose blocked or kinked?

Yes
CLEAN, REPLACE or SERVICE nozzle or hoses.

No
GO to B4.

 

B4 CHECK FOR BLOCKAGE AT WASHER PUMP OUTLET

• Disconnect hose at reservoir and check for blockage at washer pump outlet.

• Is hose blocked at washer pump outlet?

Yes
REMOVE washer pump from reservoir and CLEAN.

No
REPLACE washer pump.

 

B5 CHECK VOLTAGE AT WASHER PUMP

• Using a voltmeter or test lamp, check for voltage at washer pump by activating washer switch.

• Is there voltage?

Yes
GO to B6.

No
GO to B7.

 

B6 CHECK GROUND AT PUMP

• Using an ohmmeter, check ground at washer pump.

• Is ground functional?

No
SERVICE ground.

Yes
REPLACE pump.

 

B7 CHECK FOR POWER AT SWITCH

• Check for power at wiper switch by operating wipers.

• Do wipers operate?

Yes
GO to B8.

No
GO to B9.

 

B8 CHECK FOR POWER OUT OF WASHER SWITCH

• Using a voltmeter or test lamp, check for power out of washer switch or washer circuit.

• Is there power?

Yes
GO to B10.

No
GO to B11.

 

B9 CHECK HEATER BLOWER

• Activate heater blower.

• Is blower operational?

Yes
GO to B10.

No
SERVICE open circuit in power feed wiring.

 

B10 CHECK WIPER/WASH CIRCUIT BREAKER

• Check wiper/wash circuit breaker, refer to Section 18-01 for location.

• Is circuit breaker operational?

Yes
GO to B11.

No
REPLACE circuit breaker.

 

B11 CHECK SWITCH CIRCUITS

• Check switch circuits.

• Are switch circuits functional?

Yes
GO to B12.

No
REPLACE switch.

 

B12 CHECK FOR POWER TO SWITCH

• Using a voltmeter or test lamp, check for power to washer switch or washer circuit.

• Is there power?

Yes
SERVICE wiper/washer wiring and connectors.

No
CHECK for electrical system fault before wiper/washer switch.

 

PINPOINT TEST C: WIPERS INOPERATIVE—ALL CONTROL SWITCH POSITIONS

 

C1 CHECK FOR BATTERY VOLTAGE  

• Unplug wiper motor.

• Set control switch to HIGH.

• Check for battery voltage at Circuits 63 and 56.
  
  
  
  

Voltage both circuits
GO to C2.

Voltage OK Circuit 63, NOT OK Circuit 56
CHECK for:

• Malfunctioning wiper switch.
• Open connector.
• Open wire, Circuit 56 (DB/O). SERVICE as necessary.

No voltage
CHECK for:

• Open circuit breaker in fuse panel.
• Open connector 63 (R) SERVICE as necessary.

 

C2 PERFORM WIPER MOTOR CURRENT DRAW TEST

• Perform wiper motor current draw test as outlined.

• Is test OK?

Yes
CHECK linkage for binding. SERVICE as necessary.

No
SERVICE as necessary.

 

PINPOINT TEST D: WIPERS INOPERATIVE OR ERRATIC ON LOW — HI SPEED WORKS

 

D1 CHECK WIPER OPERATION  

• Run wipers on HI.

• Do wipers hesitate when they pass through the park position?

Yes
GO to D2.

No
GO to D4.

 

D2 CHECK GOVERNOR

• Set wiper switch in LO.

• Check voltage at governor circuits 993 (BR/W) and 58(W).

Both circuits OK.
GO to D4.

No voltage at circuit 993 (BR/W).
GO to D3.

Voltage at circuit 993 (BR/W) but no voltage at circuit 58 (W) (measured at module connector).
REPLACE IWW module.

 

D3 CHECK WIRING

• Check voltage at circuit 993 (BR/W) at wiper switch.

• Is voltage present?

Yes
SERVICE wire open between wiper switch and governor.

No
SERVICE wiper switch.

 

D4 CHECK CIRCUIT 58 (W) FOR BATTERY VOLTAGE

• Unplug wiper motor.

• Set wiper switch on LO.

• Check circuit 58 (W) for battery voltage.

• Is voltage good?

Yes
CHECK for malfunctioning wiper motor. PERFORM low speed current draw test. GO to E1. SERVICE as required.

No
CHECK for:

• Unseated connector.
• Open wire circuit 58 (W) between IWW and motor. SERVICE as required.

 

PINPOINT TEST E: WIPERS CONTINUE TO RUN WHEN SWITCH IS TURNED OFF

 

E1 WIPER PARK TEST  

• Perform wiper motor park test A1.

• Do wipers park?

Yes
GO to E2.

No
REPLACE wiper motor.

 

E2 CHECK WIPER SWITCH

• Unplug wiper switch.

• Turn ignition to RUN.

• Do wipers stop?

Yes
GO to E4.

No
GO to E3.

 

E3 CHECK INTERVAL WIPER GOVERNOR

• Plug in wiper switch.

• Turn ignition to RUN.

• Check for voltage at circuit 58 (W) at module connector.

• Is battery voltage present?

Yes
GO to E4.

No
CHECK for short in wiring circuits 56 (DB/O) or 58 (W).

 

E4 CHECK FOR VOLTAGE AT SWITCH

• Check for voltage at circuit 993 (BR/W) or 941 (BK/W) or 65 (DG) at the wiper/washer control switch output.

• Is battery voltage present?

Yes
REPLACE malfunctioning wiper control switch.

No
REPLACE malfunctioning IWW module.

 

PINPOINT TEST F: WIPERS DO NOT WIPE AFTER WASH SWITCH IS PULLED

 

F1 CHECK OPERATION

• Do wipers function normally on INT, LO, and HI?

Yes
GO to F2.

No
GO to D1.

 

F2 CHECK FOR VOLTAGE FROM WASHER SWITCH

• Activate the washer switch.

• Check for voltage at circuit 941 (BK/W) input to the IWW module.

• Is battery voltage present?

Yes
Go to F3.

No
GO to F4.

 

F3 CHECK IWW MODULE OPERATION

• Activate the washer switch.

• Measure the voltage at circuit 58 (W) at the IWW module connector.

• Is battery voltage present?

Yes
CHECK for:

• Unseated connector.
• Open circuit between IWW module and wiper motor. SERVICE as required.

No
GO to F6.

 

F4 CHECK FOR BATTERY VOLTAGE AT THE WIPER/WASHER SWITCH OUTPUT

• Activate the washer switch.

• Measure the voltage at circuit 941 (BK/W) at the wiper/washer switch.

• Is battery voltage present?

Yes
CHECK for open circuit between wiper/washer switch and IWW module. SERVICE as required.

No
GO to F5.

 

F5 CHECK FOR BATTERY VOLTAGE AT WIPER SWITCH INPUT

• Unplug wire harness connector from wiper/washer switch.

• Measure voltage at circuit 63 (R) input to wiper/washer switch.

• Is battery voltage present?

Yes
CHECK for:

• Unseated connector.
• Damaged wiper switch. SERVICE as required.

No
SERVICE open circuit between fuse panel and wiper switch.

 

F6 CHECK FOR BATTERY VOLTAGE AT INPUT TO IWW MODULE

• Check for battery voltage at circuit 63 (R) input to IWW module.

• Is battery voltage present?

Yes
REPLACE IWW module.

No
SERVICE open circuit between fuse panel and IWW module.

 

PINPOINT TEST G: WASHERS INOPERATIVE

 

G1 CHECK WIPER OPERATION

• Check operation of wipers.

• Do wipers work OK?

Yes
CHECK for:

• Low washer fluid
• Split, loose, pinched or kinked washer hose
• Malfunctioning washer pump motor
• Malfunctioning switch
• Open Circuit 941 (BK/W)
• Open connector

SERVICE or REPLACE as necessary.

No
Check for:

• Open circuit breaker in fuse panel
• Open wire, Circuit 63 (R)

SERVICE or REPLACE as necessary.

 

PINPOINT TEST H: WIPERS INOPERATIVE ON INTERVAL — LOW OR HIGH SPEED WORKS

 

H1 CHECK FOR BATTERY VOLTAGE AT CIRCUIT 65 (DG)

• Turn wiper switch to interval position.

• Check for battery voltage at circuit 65 (DG) input to the IWW module.

• Is battery voltage present?

Yes
GO to H2.

No
Go to H3.

 

H2 CHECK INTERVAL ADJUST FEATURE OF WIPER SWITCH

• Disconnect connector from wiper switch.

• Measure resistance between terminals R1 and R2 of the wiper switch as the wiper switch is rotated through the interval range.

Resistance varies uniformly
REPLACE IWW module.

Short or open
REPLACE wiper/washer switch.

 

H3 CHECK FOR BATTERY VOLTAGE AT CIRCUIT 65 (DG) AT WIPER SWITCH

• Turn wiper switch to interval position.

• Measure voltage output of wiper switch at I terminal.

• Is battery voltage present?

Yes
SERVICE open circuit between wiper/washer switch and IWW module.

No
SERVICE or REPLACE wiper switch.

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