Windshield wipers only work on high and don't come to park. I have replaced the relay and the control module. what else should I be doing replace the motor?

The is the symptom of a defective wiper switch.

Yukon what ? just a plain yukon ? 2WD or 4WD XL - Denali etc...
No pulse board . controlled by the BCM - body control module . Taking the vehicle to a qualified repair would be your best bet .
Windshield Wipers
The windshield wiper/washer switch signal circuits are inputs to the body control module (BCM) and the BCM controls wiper motor low speed operation, washer pump and high speed operation. The windshield wiper/washer switch is provided a low reference from the BCM and each of the switch signal circuits is supplied 12 volts through a resistor and monitored within the BCM. During LOW or INTERMITTENT operation the wiper switch low signal circuit is closed to the low reference circuit through a series of resistors within the switch assembly and the signal circuit voltage monitored by the BCM will depend on the switch contact location to the resistor assembly. During HIGH or WASH operation the high and wash switch signal circuits are closed directly to the low reference circuit within the switch assembly and nearly all the signal circuit voltage will be dropped across the BCM resistors. The BCM controls the wiper motor through the Wiper Relay and the Wiper High Relay. During any wiper motor function that uses low speed the BCM supplies the voltage to energize the Wiper Relay and battery voltage will be supplied from the Wiper Relay through the de-energized Wiper High Relay to the wiper motor low speed control circuit. During high speed wiper motor operation the Wiper Relay is energized as in low speed and the BCM provides a ground to energize the Wiper High Relay and the battery voltage is supplied to the wiper motor high speed control circuit. Wiper motor park operation is controlled by the BCM using an input from the park switch within the wiper motor assembly. The BCM supplies the park switch signal circuit 12 volts through a resistor then monitors the circuit. Whenever the wiper motor is out of the park position the park switch signal circuit is closed to ground and nearly all the signal circuit voltage will be dropped across the BCM resistor. When the wiper switch is turned to the OFF position while the wiper motor is somewhere in mid-cycle, the BCM will continue to operate the motor until the wipers reach the park position. If the ignition is turned OFF while the wipers are in mid-cycle, the wipers will stop immediately where they are and the BCM will park the wipers the next time the ignition is cycled ON.

Principles of Operation
The windshield wiper motor receive inputs from the following:

• multifunction switch
• lighting control module (LCM)
• ignition switch
• battery junction box (BJB)
• central junction box (CJB)

The following components are integrated into the windshield wiper motor:

• windshield wiper motor module
• high/low speed relay
• run/park sensor (Hall effect)
• washer pump relay

High Speed Windshield Wipers
High speed is activated when the multifunction switch supplies ground to the windshield wiper motor module inputs. The windshield wiper motor module then supplies ground to the run/park sensor and high/low relay coil, activating the relay with voltage supplied from the ignition switch (RUN/ACC) through the central junction box (CJB). When the windshield wiper motor module receives voltage from the run/park sensor, it removes ground from the run/park sensor, deactivating it. The windshield wiper motor continues to operate from voltage connected through the run/park sensor until the Hall effect senses the magnet in the motor. When the Hall effect senses the magnet in motor the windshield wiper motor returns to the park position, the internal run/park sensor grounds the windshield wiper motor module input and the windshield wiper motor module removes ground from the windshield wiper high/low relay coil, deactivating the high/low relay and windshield wiper motor. The windshield wiper motor module continues to cycle the windshield wipers until the inputs from the multifunction switch are changed from the high speed position.
Low Speed Windshield Wipers
Low speed is activated when the multifunction switch supplies a specific ground to the speed inputs of the windshield wiper motor module. The windshield wiper motor module then supplies ground to only the windshield wiper run/park relay coil, activating it. When the windshield wiper run/park relay is activated, the deactivated windshield high/low relay connects voltage to the windshield wiper motor low input activating the wiper motor. The windshield wiper motor module continues to operate the windshield wiper motor in the same manner as in high speed, but in low speed with the wiper motor connected to the low speed input.
Intermittent Speed Windshield Wipers
The intermittent wiper speed is activated with grounds controlled by the multifunction switch inputs to the windshield wiper motor module. The windshield wiper motor module then activates the windshield wiper run/park relay coil and switches voltage through the windshield wiper high/low relay. The high/low relay remains deactivated, supplying the voltage to the wiper motor low speed input and activates the windshield wiper motor. When the windshield wiper motor module receives the grounded input, the motor continues to operate until Hall effect sensors senses the wiper motors magnet, which turns off the run/park sensor output to the windshield wiper run/park software, deactivating the relay and disconnecting voltage to the wiper motor. The windshield wipers remain parked until the windshield wiper motor module completes a time-out and then repeats the intermittent windshield wiper cycle.
Washer System
The windshield washer is activated by the internal wiper motor module when it receives a ground from the multifunction switch between the washer input. Dependent on the correct ground, the internal wiper motor modules activates the windshield washer relay (internal) by grounding the respective relay coil. When the relay is activated, it connects voltage to the washer pump while the washer level switch provides ground to the washer pump.
Default Mode
The windshield wiper motor defaults to this mode when the run/park sensor does not sense the hall effect magnet inside wiper motor. This can be caused by obstruction of the windshield wipers or a binding linkage. The windshield wiper motor will continue to operate in a high/low speed condition for a period of 60 seconds.

Symptom Chart
Symptom Chart Condition Possible Sources Action

• The wipers are inoperative

• Multifunction switch
• Circuitry
• Ignition switch
• Windshield wiper motor

• Go To Pinpoint Test A .

Do you know how to test automotive electrical circuits using a factory diagnostic test procedure flow chart ?

PINPOINT TEST A: THE WIPERS ARE INOPERATIVE Test Step Result / Action to Take A1 CHECK CIRCUITS 65 (DG) AND 2025 (RD/YE) FOR VOLTAGE

• Key in OFF position.
• Disconnect: Windshield Wiper Motor C125.
• Key in ON position.
• Measure the voltage between windshield wiper C125 pin 5, circuit 2025 (RD/YE), harness side and ground; and between windshield wiper motor C125 pin 8, circuit 65 (DG), harness side and ground.
• Are the voltages greater than 10 volts?

Yes
GO to A2 .

No
REPAIR the circuit(s) in question. TEST the system for normal operation. A2 CHECK CIRCUITS 57 (BK) AND 676 (PK/OG) FOR OPENS

• Key in OFF position.
• Measure the resistance between windshield wiper C125 pin 6, circuit 57 (BK), harness side and ground; and between windshield wiper motor C125 pin 3, circuit 676 (PK/OG), harness side and ground.
• Are the resistances less than 5 ohms?

Yes
GO to A3 .

No
REPAIR the circuit(s) in question. TEST the system for normal operation. A3 CHECK THE MULTIFUNCTION SWITCH

• Disconnect: Multifunction Switch C202b.
• Carry out the multifunction switch component test. Refer to Wiring Diagrams Cell 149 for schematic and connector information.
  
• Does the multifunction switch pass the component test?

Yes
GO to A4 .

No
INSTALL a new multifunction switch. REFER to Section 211-05 . A4 CHECK CIRCUIT 57 (BK) FOR AN OPEN

• Measure the resistance between C202b pin 5, circuit 57 (BK), harness side and ground.
• Is the resistance less than 5 ohms?

Yes
GO to A5 .

No
REPAIR the circuit. TEST the system for normal operation. A5 CHECK CIRCUITS 56 (DB/OG), 58 (WH), 61 (YE/RD), AND 63 (RD) FOR OPENS

• Using the following table, measure the resistance between the multifunction switch C202b harness side and the windshield wiper motor C125 harness side:
  
  Multifunction 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 1, circuit 61 (YE/RD) pin 1, circuit 61 (YE/RD) pin 4, circuit 63 (RD) pin 9, circuit 63 (RD)
• Are the resistances less than 5 ohms?

Yes
GO to A6 .

No
REPAIR the circuit(s) in question. TEST the system for normal operation. A6 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?

Yes
GO to A7 .

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. A7 CHECK THE WINDSHIELD WIPER MOTOR

• Key in OFF position.
• Disconnect: Windshield Wiper Motor C125.
• Carry out the windshield wiper motor component test as outlined in this section.
• Does the windshield wiper motor pass the component test?

Yes
The system is operating correctly at this time. The concern may have been caused by binding or incorrect pivot arm adjustment. REFER to Windshield Wiper Blade and Pivot Arm Adjustment in this section. TEST the system for normal operation.

No
INSTALL a new windshield wiper motor. REFER to Windshield Wiper Motor in this section.

Your windshield wiper's are computer controlled by the BCM - body control module . The wiper switch is an input to the BCM , which energizes two different relay's to turn on the wiper's . Taking the vehicle to a qualied repair shop an having diagnostic's run would be your best bet , unless you have a professional scanner that can read DTC'S - diagnostric trouble code's in the BCM !
DTC B3715 00: Front Wiper Relay Drive Circuit
DTC B3875 00: Wiper High Speed Relay Circuit
DTC B3922 00: Front Wiper Function Select Circuit
This is always the first step in the diagnostic process . An if you do not know how they work ,reading factory service manual info. should be done .
Circuit/System Description
The body control module (BCM) controls the wiper motor based on input from the windshield wiper washer switch. The BCM monitors the wiper washer switch through three separate signal circuits and a ground circuit. The windshield wiper switch high signal circuit is used to determine high speed wiper operation, the windshield wiper switch low signal is used to determine low speed, intermittent, and mist operation through the use of a resistor ladder, and windshield washer switch signal circuit is used to determine washer operation.
Your best bet , take it to a qualified repair shop.

There are two relay's in the under hood fuse / relay box . Wiper relay an wiper relay 2 . Maybe one is bad . also check fuse #14 25 amp. Wiper fuse.Plus the BCM - body control module has a hand in making the wipers work . Are you familiar with automotive electronic control modules ?
The Wiper/Washer System consists of the following components:
• Windshield wiper/washer switch
• Body control module (BCM)
• Wiper micro relay
• Wiper 2 relay
• Wiper diode
• Windshield wiper motor
• Windshield washer pump
• Windshield washer nozzles
• Windshield washer solvent container
• Windshield wiper arm and blade assemblies
• Windshield wiper transmission
• WIP/WASH 10A fuse
• WIPER 25A fuse

Wiper/Washer System Description
The body control module (BCM) controls wiper motor low speed operation. The washer pump and high speed operation are controlled directly by the wiper/washer switch. The windshield wiper/washer switch supplies voltage on the signal circuits to the BCM for windshield wiper/washer operation. When WASH, MIST, DELAY, LOW, or HIGH is detected, the BCM energizes the wiper micro relay by suppling voltage to the relay coil. This allows battery voltage from the WIPER fuse to flow through the relay switched input then through the contacts and out the relay switched output to the wiper 2 relay switch contacts. Since the wiper 2 relay switch contacts are normally closed to the low speed circuit of the windshield wiper motor, the motor will operate at low speed.

Do you have any speed !

Did you check the wiper relay's in the under hood fuse box ? There are two ,wiper run/park relay & wiper high low relay ! Also ,did you check fuse's ? fuse # 11 - 30amp location cental juction box . The wiper switch is a input to the GEM module . Generic electronic module . The module in most cases isn't the problem ! Learning how to test these electronic systems is , people do not know how to test so they just replace parts . What they should do is take the vehicle to ford certified Technician who has the knowledge and testing equipment to find an fix it .

The generic electronic module (GEM) receives inputs from the following:

• multifunction switch
• anti-lock brake control module (vehicle speed signal [VSS])
• ignition switch

The GEM uses these inputs to control the outputs to the following:

• windshield wiper high/low relay
• windshield wiper run/park relay
• windshield washer relay
• rear wiper motor relay
• rear window washer relay
• 
  GEM Diagnostic Trouble Code (DTC) Index DTC Description Source Action B1240 Wiper Washer Rear Pump Relay Circuit Failure GEM GO to Pinpoint Test K . B1241 Wiper Washer Rear Pump Relay Circuit Short to Battery + GEM GO to Pinpoint Test K . B1342 ECU is Defective GEM CLEAR the DTCs. REPEAT the GEM self-test. If DTC B1342 is retrieved, INSTALL a new GEM. REFER to Section 419-10 . B1431 Wiper Brake/Run Relay Circuit Failure GEM If the windshield wipers are inoperative, GO to Pinpoint Test B .
  If the windshield wipers stay on continuously, GO to Pinpoint Test C . B1432 Wiper Brake/Run Relay Circuit Short to Battery GEM GO to Pinpoint Test B . B1434 Wiper Hi/Low Speed Relay Coil Circuit Failure GEM GO to Pinpoint Test D . B1436 Wiper Hi/Low Speed Relay Coil Circuit Short to Battery GEM GO to Pinpoint Test D . B1438 Wiper Mode Select Switch Circuit Failure GEM If the windshield wipers are inoperative, GO to Pinpoint Test B .
  If both the windshield and rear window wipers are inoperative, GO to Pinpoint Test L . B1441 Wiper Mode Select Switch Circuit Short to Ground GEM GO to Pinpoint Test C . B1446 Wiper Park Sense Circuit Failure GEM If the intermittent windshield wiper speed does not operate correctly, GO to Pinpoint Test E .
  If the speed dependent interval mode does not operate correctly, GO to Pinpoint Test G .
  If both windshield and rear wipers are inoperative, GO to Pinpoint Test L . B1450 Wiper Wash/Delay Switch Circuit Failure GEM If the intermittent windshield wiper speed does not operate correctly, GO to Pinpoint Test E .
  If the wash and wipe function does not operate correctly, GO to Pinpoint Test F .
  If both the windshield and rear wipers are inoperative, GO to Pinpoint Test L . B1453 Wiper Wash/Delay Switch Circuit Short to Ground GEM If the windshield wipers stay on continuously, GO to Pinpoint Test C .
  If the wash and wipe function does not operate correctly, GO to Pinpoint Test F . B1458 Wiper Washer Pump Motor Relay Circuit Failure GEM GO to Pinpoint Test F . B1460 Wiper Washer Pump Motor Relay Coil Circuit Short to Battery GEM GO to Pinpoint Test F . B1473 Wiper Low Speed Circuit Motor Failure GEM If the windshield wipers are inoperative, GO to Pinpoint Test B .
  If the windshield wipers do not operate at high or low speed correctly, GO to Pinpoint Test D .
  If the intermittent windshield wiper speed does not operate correctly, GO to Pinpoint Test E . B1475 Accessory Delay Relay Contact Short to Battery GEM REFER to Section 501-11 . B1476 Wiper High Speed Circuit Motor Failure GEM If the windshield wipers are inoperative, GO to Pinpoint Test B .
  If the windshield wipers do not operate at high or low speed correctly, GO to Pinpoint Test D .
  If the intermittent windshield wiper does not operate correctly, GO to Pinpoint Test E . B1611 Rear Wiper Mode Switch Circuit Failure GEM GO to Pinpoint Test H . B1614 Rear Wiper Mode Switch Circuit Short to Ground GEM GO to Pinpoint Test I . B1820 Rear Wiper Motor Up Relay Circuit Short to Battery + GEM GO to Pinpoint Test H . B1839 Rear Wiper Motor Circuit Failure GEM GO to Pinpoint Test H . - All other DTCs. GEM REFER to Section 419-10

Have you done a Probe Test on the vehicle? A Probe Light Tester can help you locate a short in your cars electrical system. To learn what a Probe Tester is and How to use it, watch the following video: https://www.youtube.com/watch?v=tXzKcEyIOq8

If your not familiar with automotive electronics an module control of components , I suggest you take it to the dealer . They have the tools to diagnose this type problem !
The Wiper/Washer System consists of the following components:
?€¢
Windshield wiper/washer switch

?€¢
Body control module (BCM)

?€¢
Wiper PCB relay

?€¢
Wiper high PCB relay

?€¢
Windshield wiper motor

?€¢
Windshield washer fluid pump

?€¢
Windshield washer fluid level switch

?€¢
WPR fuse 25 A

?€¢
WSW fuse 10 A

Low Speed Operation
When the wiper switch is in the low speed position, ground is applied through the switch internal resistor and the wiper switch low signal circuit to the body control module (BCM). In response to this signal, the BCM energizes the WIPER PCB relay by applying battery voltage through the wiper relay control circuit to the coil side of the relay. This allows battery positive voltage from the WPR fuse to flow through the switch input side of the WIPER PCB relay and out to the switch input side of the WIPER HIGH PCB relay. Since the wiper high relay is de-energized and its switch contacts are normally closed to the low speed control circuit of the windshield wiper motor, the motor will operate at low speed.
High Speed Operation When the wiper switch is in the high speed position, ground is applied through the windshield wiper switch high signal circuit to the body control module (BCM) indicating the wiper high speed request. In response to this signal, the BCM then energizes the wiper PCB relay, as stated above, and the wiper high PCB relay by applying ground through the control circuit to the coil side of the relay. With the wiper high relay energized and its switch contacts closed to the high speed control circuit of the wiper motor, the motor will operate at high speed.
Wiper motor high speed operation and the wiper high speed PCB relay can also be commanded ON/OFF by using a scan tool. Refer to Control Module References.
DTC B3715 02: Front Wiper Relay Drive Circuit Short to Ground
DTC B3875 00: Wiper High Speed Relay Circuit
DTC B3922 00: Front Wiper Function Select Circuit
You could Have a switch problem , BCM problem ,PCB relay problem , the pcb relays are non serviceable an the whole under hood fuse box would need to be replaced . Malfunctioning motor bad ground some where etc.....

This is a complex wiper system . Here are all the components involved !
The Wiper/Washer System consists of the following components:
?€¢
Windshield wiper/washer switch

?€¢
Body control module (BCM)

?€¢
Wiper 1 relay

?€¢
Wiper 2 relay

?€¢
Wiper diode

?€¢
Windshield wiper motor

?€¢
Windshield washer pump

?€¢
Windshield washer nozzles

?€¢
Windshield washer solvent container

?€¢
Windshield wiper arm and blade assemblies

?€¢
Windshield wiper transmission

?€¢
WIPER/SW 10A fuse

?€¢
WIPER 25A fuse

Circuit/System Description
The body control module (BCM) controls the wiper motor based on input from the windshield wiper washer switch. The BCM monitors the wiper washer switch through three separate signal circuits and a ground circuit. The windshield wiper switch high signal circuit is used to determine high speed wiper operation, the windshield wiper switch low signal is used to determine low speed, intermittent, and mist operation through the use of a resistor ladder, and windshield washer switch signal circuit is used to determine washer operation. The windshield wiper motor park operation is controlled by the BCM. The BCM recieves an input from the park switch to determine wiper blade position. When the wiper blades are at the bottom of the windshield glass in park position the wiper park switch will open and the circuit will be pulled up to B+ by the BCM. The park signal will be pulled to ground by the wiper motor park switch while the wiper blades are not in the park position.
The BCM controls the windshield wiper motor through two output controls, controlling two relays which determine the desired wiper speed, high or low
Diagnostic Trouble Codes (DTCs)
The body control module (BCM) monitors the voltage on the windshield wiper switch signal 2 circuit for diagnostic purposes. If the circuit is shorted to voltage while the driver is commanded OFF, the BCM will store DTC B3715. If the circuit is shorted to ground while the driver is commanded ON, the BCM will store DTC B3715. Refer to DTC B3715.
It would be best to have a factory scan tool to diagnose this problem . it would make it easier anyway .
It

Did you check for voltage at the wiper fuse? My info says that fuse is hot all the time. Use a digital multimeter. Everything off, take a reading across battery posts, the generic spec for a full charge is around 12.6 volts. You should get close to same reading at the wiper fuse, hopefully. When checking voltage at the fuse, use chassis ground not the other leg of fuse. There are wiper relays, those are pcb relays, they are soldered into the fuse box, you can't pull them out. Your bcm is also involved with those relays. Your multifunction switch basically tells the bcm you turned on your wipers, then the bcm controls voltage or ground for the relays. You can see wire color for hi and lo speed voltage. Maybe a problem with fuse box or wiring circuit if voltage is low? I hope this was of some help?