Pinpoint Test D: The Intermittent Wiper Speed Does Not Operate Correctly

Refer to appropriate SYSTEM WIRING DIAGRAMS article, Wipers and Washers for schematic and connector information.

Normal Operation 

The windshield wiper motor receives open and ground inputs from the multi-function switch through circuits 56 (DB/OG), 58 (WH), 61 (YE/RD) and 63 (RD). When a wiper function is selected, the multi-function switch grounds 1 of several combinations of these 4 circuits. The windshield wiper motor interprets these ground signals and performs the action requested. The multi-function switch is grounded through circuit 57 (BK).

This pinpoint test is intended to diagnose the following:

• Wiring, terminals or connectors
• Multi-function switch
• Windshield wiper motor

PINPOINT TEST D: THE INTERMITTENT WIPER SPEED DOES NOT OPERATE CORRECTLY 

1. D1 CHECK THE MULTI-FUNCTION SWITCH 
   • Key in OFF position.
   • Disconnect: Multi-function switch C202b
   • Carry out the multi-function switch component test. Refer to appropriate COMPONENT TESTING article.
   • Does the multi-function switch pass the component test? 
   1. YES  : Go to  D2.
   2. NO  : INSTALL a new multi-function switch. REFER to STEERING COLUMN SWITCHES article.
2. D2 CHECK CIRCUITS 56 (DB/OG), 58 (WH) AND 63 (RD) FOR OPENS 
   • Disconnect: Windshield Wiper Motor C125
   Fig 1: Checking Circuits For Open
   Courtesy of FORD MOTOR CO.
   • Using the following table, measure the resistance between multi-function switch C202b harness side and windshield wiper motor C125 harness side:

     Multi-function Switch C202b	Windshield Wiper Motor C125
     Pin 6, circuit 56 (DB/OG)	Pin 10, circuit 56 (DB/OG)
     Pin 3, circuit 58 (WH)	Pin 11, circuit 58 (WH)
     Pin 4, circuit 63 (RD)	Pin 9, circuit 63 (RD)

   • Are the resistances less than 5 ohms? 
   1. YES  : Go to  D3.
   2. NO  : REPAIR the circuit. TEST the system for normal operation.
3. D3 CHECK CIRCUITS 56 (DB/OG), 58 (WH) AND 63 (RD) FOR A SHORT TO GROUND 
   Fig 2: Checking Circuits For Short To Ground
   Courtesy of FORD MOTOR CO.
   • Using the following table, measure the resistance between windshield wiper motor C125 harness side and ground.

     Windshield Wiper Motor C125	Ground
     Pin 10, circuit 56 (DB/OG)	ground
     Pin 11, circuit 58 (WH)	ground
     Pin 9, circuit 63 (RD)	ground

   • Is the resistance greater than 10,000 ohms? 
   1. YES  : Go to  D4.
   2. NO  : REPAIR the circuit(s) in question. TEST the system for normal operation.
4. D4 CHECK FOR SHORTS IN THE WINDSHIELD WIPER MOTOR HARNESS 
   • Measure the resistance at the windshield wiper motor electrical connector between the circuits shown in the table.

     Windshield Wiper Motor C125	Windshield Wiper Motor C125
     Pin 10, circuit 56 (DB/OG)	Pin 11, circuit 58 (WH)
     	Pin 1, circuit 61 (YE/RD)
     	Pin 9, circuit 63 (RD)
     Pin 11, circuit 58 (WH)	Pin 1, circuit 61 (YE/RD)
     	Pin 9, circuit 63 (RD)
     Pin 1, circuit 61 (YE/RD)	Pin 9, circuit 63 (RD)

   • Is the resistance greater than 10,000 ohms for all measurements? 
   1. YES  : Go to  D5.
   2. NO  : REPAIR the circuit. TEST the system for normal operation.
5. D5 CHECK FOR CORRECT WIPER MOTOR OPERATION 
   • Disconnect all wiper motor connectors.
   • Check for:
     • corrosion.
     • pushed-out pins.
   • Connect all wiper motor connectors and make sure they seat correctly.
   • Operate the system and verify the concern is still present.
   • Is the concern still present? 
   1. YES  : INSTALL a new windshield wiper motor. REFER to Wiper Motor .
   2. NO  : The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. TEST the system for normal operation.