Torrent rear wiper motor

Sounds like you might have a bad multifunction switch. You can test the outputs of the switch to confirm.

Do you know how these wipers Work / what controls them ? Do you know what a smart junction box is ?
Rear Window Wiper Operation
The rear wiper motor is controlled by the SJB. The SJB supplies power to the rear wiper motor from the integrated rear wiper relay. The SJB will activate the relay when all of the following conditions are met:

• Ignition switch is in the ON position
• Liftgate glass and liftgate are closed
• Multifunction switch is in the ON or INTERMITTENT position

The SJB also supplies voltage to the rear wiper motor from SJB fuse 21 (10A) when the ignition switch is in the ON position. This power feed is used to continue the wipe cycle when the multifunction switch is turned to the OFF position. The SJB receives inputs from the multifunction switch that applies ground to the low speed wipe input or applies ground to the intermittent wipe input. When either of these circuits are grounded, the SJB activates the integrated rear wiper relay and power is supplied to the rear wiper motor to move the rear wiper motor from the PARK position. An internal switch in the rear wiper motor then moves to the RUN position which connects the accessory relay power to the rear wiper motor. When the rear wiper motor returns to the PARK position, the internal switch in the rear wiper motor moves back to the PARK position. If the multifunction switch is in the ON position, the rear wiper relay is still activated, power is supplied to the rear wiper motor, and the wipe cycle starts again. If the multifunction switch is in the INTERMITTENT position, the rear wiper relay does not activate until the predetermined dwell time has elapsed, at which time the SJB activates the rear wiper relay and the wipe cycle starts again.

Do you know what DTC'S - diagnostic trouble codes are ?
Smart Junction Box (SJB) Diagnostic Trouble Code (DTC) Index DTC Description Source Action B1244 Wiper Rear Motor Run Relay Coil Circuit Failure SJB If the rear wiper is inoperative, Go To Pinpoint Test B . If the rear wiper is always ON, Go To Pinpoint Test D . B1245 Wiper Rear Motor Run Relay Coil Circuit Short to Battery SJB Go To Pinpoint Test B . B1614 Wiper Rear Mode Select Switch Circuit Failure SJB Go To Pinpoint Test D .
Did you have it checked for DTC'S ?

Did you check the fuse ? Do you hear the wiper motor running ? If the fuse is good you would need to test the electrical circuit for the wiper motor ,viewing a wiring diagram an then use a DVOM - digital volt ohmmeter to test
What body type is it ? Vin 6 or 3 could have a circuit breaker for power supply or fuse ,both are located in the rear fuse block .

Rear Wiper/Washer System Components
The rear wiper/washer system consists of the following components:
• Rear window wiper motor
• Rear window washer fluid pump
• Rear wash relay
• Rear window wiper/washer switch
• RR wiper 15A circuit breaker
• WASH 20A fuse
Rear Wiper/Washer System Controls
• Body control module (BCM)
• Liftgate control module (LGM)
• Rear wiper/washer switch

Here is how it is controlled

Rear Wiper/Washer System Operation
The rear window wiper/washer switch is an input to the BCM. The requested rear wiper mode is sent to the liftgate control module (LGM) by the BCM as a message on the serial data circuit, and the rear window wiper motor is controlled by the LGM. The switch power circuit to the rear wiper/washer switch is a 12-volt reference supplied by the BCM during ignition on, accessory or RAP power modes. The rear wiper/washer switch is a series of resistors and the switch position is determined by the voltage of the rear wiper/washer switch signal circuit to the BCM. The rear wiper/washer switch has continuity at all times and the BCM expects a rear wiper/washer switch signal voltage in all switch positions including OFF. The rear wiper motor is supplied battery positive voltage and ground. The LGM controls rear wiper motor operation through the rear wiper motor control circuit. The rear wiper motor control circuit is supplied a battery positive reference voltage by the rear wiper motor module and is pulse width modulated to ground by the LGM. The duty cycle of the pulse width modulation determines the rear wiper motor operating mode. The liftglass and liftgate ajar switches are inputs to the LGM and must be in an inactive state in order for rear wiper washer system operation to be enabled. When an ajar switch is active the LGM suspends wiper motor operation directly and sends the ajar switch status messages over the serial data circuit enabling the BCM to suspend washer pump operation. The rear window washer pump is controlled by the BCM through the rear washer relay. Battery positive voltage is supplied to the coil and switch sides of the rear washer relay. When the rear window wash request is active the BCM energizes the relay by grounding the relay coil through the rear washer relay control circuit. When the relay is energized battery positive voltage to the relay switch is supplied to the washer pump control circuit.

Your best bet mite be to have a qualified repair shop check for codes in the BCM or LGM
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DTC B1017 or B3970

The rear wiper motor is supplied battery positive voltage and ground. The liftgate control module controls rear wiper motor operation through the rear wiper motor control circuit. The rear wiper motor control circuit is supplied a battery positive reference voltage by the rear wiper motor module and is pulse width modulated to ground by the liftgate control module. The duty cycle of the pulse width modulation determines the rear wiper motor operating mode.

Can you move the wiper by hand ? Which does your vehicle have ?
WDA/Z88 The rear wiper is controlled based on an input from the rear wiper/washer portion of the multifunction switch. When closed, the wiper ON and wiper DELAY switches provide a unique voltage signal to the rear window wiper motor indicating the desired speed. Each switch has a unique resistor that drops the voltage to a specified value which is interpreted by the rear window wiper motor as ON or DELAY. The rear wiper motor receives B+ voltage from the I/P fuse block and accessory voltage from the body control module (BCM).
W49 The rear wiper is controlled based on an input from the rear wiper/washer switch. When closed, the wiper ON switch provides a voltage signal to the rear window wiper motor indicating rear wiper operation is requested. The rear wiper motor receives B+ voltage from the I/P fuse block and accessory voltage from the body control module (BCM).
Do you know how to do electrical testing ?
WDA/Z88

1. Ignition OFF, disconnect the harness connector X1 at the multifunction switch.
2. Ignition ON, verify a test lamp illuminates between the ignition circuit terminal 4 and ground.
?‡'
If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance. If the circuit tests normal, refer to Power Mode Mismatch.

3. Ignition OFF, connect the harness connector at the multifunction switch. Disconnect the harness connector at the rear window wiper motor.
4. Test for less than 20 ohms between the ground circuit terminal B and ground.
?‡'
If greater than the specified range, test the ground circuit for an open/high resistance.

5. Ignition ON, verify a test lamp illuminates between the B+ circuit terminal A and ground.
?‡'
If the test lamp does not illuminate, test the B+ circuit for an open/high resistance.

6. Verify a test lamp illuminates between the ignition circuit terminal E and ground.
?‡'
If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance.

7. Rear wiper switch in the ON position, test for B+ between the signal circuit terminal D and ground.
?‡'
If less than the specified value, test the signal circuit for an open/high resistance. If the circuit tests normal, test or replace the multifunction switch.

8. Rear wiper switch in the DELAY position, test for B+ between the signal circuit terminal D and ground.
?‡'
If less than the specified value, test or replace the multifunction switch.

9. If all circuits test normal, test or replace the rear window wiper motor.

W49

1. Ignition OFF, disconnect the harness connector at the rear wiper switch.
2. Ignition ON, verify a test lamp illuminates between the ignition circuit terminal 6 and ground.
?‡'
If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance. If the circuit tests normal, refer to Power Mode Mismatch.

3. Ignition OFF, connect the harness connector at the rear wiper switch. Disconnect the harness connector at the rear window wiper motor.
4. Test for less than 20 ohms between the ground circuit terminal B and ground.
?‡'
If greater than the specified range, test the ground circuit for an open/high resistance.

5. Ignition ON, verify a test lamp illuminates between the B+ circuit terminal A and ground.
?‡'
If the test lamp does not illuminate, test the B+ circuit for an open/high resistance.

6. Verify a test lamp illuminates between the ignition circuit terminal E and ground.
?‡'
If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance.

7. Rear wiper switch in the ON position, verify a test lamp illuminates between the signal circuit terminal D and ground.
?‡'
If the test lamp does not illuminate, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, test or replace the I/P switch assembly.

8. If all circuits test normal, test or replace the rear window wiper motor.

Component Testing

Do you know how

the switch that you turn to ge the wiper to wipe -- controls the power to the wiper motor. You need check the wiring from the switch to the wiper motor -- for break or disconnects. you may have to replace the switch oor install a dash mount switch instead And bypass the stock switch.

The motor is protected with a fuse and a circuit breaker. Check both to see if either need to be replaced. The fuse box is under the dash on the drivers side near the door. Open the box and look on the lid. You will find a list of all fuses, their amperage and what they protect. Remove the correct fuse by pulling it out with the plastic "fuse puller" that is stored in the fuse box cover. It looks similar to a short pair of tweezers.The fuse is burned out and needs to be replaced if the filament in the fuse is burned in half. If the fuse is good, you would next want to remove the wiper motor and use a volt meter to check for voltage between the wires that plug into the motor. Be sure to check for voltage with the wiper motor switch turned on. If you have power then you have bad motor, if you don't have power, you have an electrical problem.

The breaker should only turn off if the motor overheats due to something like the wiper being frozen to the window and not able to operate when you turn it on. This should reset once the wipers are turned off and the motor cools.

sometimes there are multiple fuses. If they are all good then the motor might be burned out, if not, then you have a ground somewhere but I doubt it.

You probably have a poor electrical connection somewhere between the switch and the motor.

Check you ground you could have an exposed wire that is grounding out and draining the battery. This could be a BIG fire hazard.

my 2004 expedition had same problem, if you take apart the shaft that goes thru the glass it will be full of dirt, clean ,lubricate and reinstall, you may have to replace the O-ring on the shaft. a 20 minute job, very easy fix