Rear Wiper Motor - Forester Subaru Cars & Trucks

There are something's involved that you are not aware of , or familiar with . Electronic control modules .
Rear Wiper/Washer System Controls
• Body control module (BCM)
• Liftgate control module (LGM)
• Rear wiper/washer switch
Do you know what a serial data network is ?
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 , take it to a qualified repair shop and have it checked for DTC'S - diagnostic trouble codes .
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.
DTC B3799

2
Turn the ignition ON.
Operate the rear wiper switch through all the switch positions.
Does the rear window wiper operate normally?
--
YES - Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems
NO - Go to Step 3
3
Install a scan tool.
Display the liftgate control module data list.
Observe the following parameters while operating the respective switches. Refer to Scan Tool Data List for typical values.
• Liftgate Ajar Switch
• Liftglass Ajar Switch
Did the scan tool indicate the correct switch positions?
--
Go to Step 4
Go to Courtesy Lamps Inoperative in Lighting Systems
4
Observe the requested rear wiper parameter in LGM data list.
Operate the rear wiper switch through all the switch positions.
Does the scan tool indicate the correct requested rear wiper parameter in relation to the switch position?
--
Go to Step 5
Go to Step 6

There is a nut under the black plastic bezel that needs to be removed. Here is the complete procedure for you to look at. Its possible that your arm isn't adjust at wiper motor...

REMOVAL
- Disconnect and isolate the battery negative cable.
- Remove the rear wiper arm from the rear wiper motor output shaft. (Refer to 8 - ELECTRICAL / REAR WIPERS / WASHERS/REAR WIPER ARM - REMOVAL).
- Using a small thin-bladed tool, gently pry at the notch in the base of the rear wiper motor output shaft bezel to unsnap the nut cover from the bezel (REAR WIPER MOTOR OUTPUT SHAFT NUT REMOVE/INSTALL). Be certain to take proper precautions to protect the outer tailgate panel and its paint finish from damage during this procedure.
- Remove the nut that secures the rear wiper motor output shaft to the outer swing gate panel (REAR WIPER MOTOR OUTPUT SHAFT NUT REMOVE/INSTALL).
- Remove the bezel and gasket from the rear wiper motor output shaft.
- Remove the trim panel from the tailgate inner panel. (Refer to 23 - BODY/SWING GATE/TRIM PANEL - REMOVAL).
- Disconnect the tailgate wire harness connector for the flip-up glass ajar switch from the flip-up glass latch connector receptacle.
- Disconnect the tailgate wire harness connector for the rear wiper motor from the motor connector receptacle (REAR WIPER MOTOR REMOVE/INSTALL).
- Loosen the two screws that secure the rear wiper motor mounting bracket to the top of the tailgate inner panel.
- Slide the rear wiper motor and mounting bracket forward far enough to disengage the two mounting screws from the keyed slots in the top of the tailgate inner panel.
- Remove the rear wiper motor and mounting bracket from the tailgate as a unit.



1 - BEZEL AND GASKET
2 - OUTPUT SHAFT
3 - TAILGATE OUTER PANEL
4 - NUT
5 - NUT COVER

What you will need to do is to remove the small plastic cap on the wiper arm by prying it off with a screw driver. Then remove the nut that holds the arm onto the shaft. Then get yourself a battery cable puller (from auto parts store) and pull the arm off of the shaft..



1 - SPARE TIRE
2 - WRENCH
3 - FLIP-UP GLASS
4 - PARK RAMP
5 - REAR WIPER ARM
6 - PIVOT COVER

Hello,

1. Disconnect the cable running to the negative terminal on the car's battery. To do this, loosen the nut on the cable clamp until the clamp is loose enough for you to slide the cable clamp off the negative battery terminal.
2. Pull the wiper arm away from the rear windshield until the wiper arm locks into a vertical or semi-vertical position or is perpendicular to the rear windshield.
3. Remove the nut holding the wiper arm assembly to the rear wiper motor.
4. Pull the wiper arm off the wiper motor assembly.
5. Unplug the rear wiper motor plug/harness.
6. Remove the screws holding the rear wiper motor to the inside of the vehicle at the base of the rear window.
7. Pull the rear wiper motor off.
8. Install the new wiper motor and put the wiper motor and arm assembly back on the vehicle by reversing the completed steps.

From ehow.com

I hope this helps

REMOVAL

1. Disconnect and isolate the battery negative cable.
2. Remove the rear wiper arm from the rear wiper motor output shaft.
3. Using a small thin-bladed tool, gently pry at the notch in the base of the rear wiper motor output shaft bezel to unsnap the nut cover from the bezel .Be certain to take proper precautions to protect the outer tailgate panel and its paint finish from damage during this procedure.
4. Remove the nut that secures the rear wiper motor output shaft to the outer swing gate panel
5. Remove the bezel and gasket from the rear wiper motor output shaft.
6. Remove the trim panel from the tailgate inner panel.
7. Disconnect the tailgate wire harness connector for the flip-up glass ajar switch from the flip-up glass latch connector receptacle.
8. Disconnect the tailgate wire harness connector for the rear wiper motor from the motor connector receptacle
9. Loosen the two screws that secure the rear wiper motor mounting bracket to the top of the tailgate inner panel.
10. Slide the rear wiper motor and mounting bracket forward far enough to disengage the two mounting screws from the keyed slots in the top of the tailgate inner panel.
11. Remove the rear wiper motor and mounting bracket from the tailgate as a unit.

To Install just reverse steps

Front Wiper Motor Removal & Installation

NOTE A new wiper motor assembly comes with the linkage arm installed.

1. Before servicing the vehicle, refer to the Precautions Section.
2. Remove the windshield wiper mounting arm and pivot shaft
   WARNING Do not remove the wiper motor linkage arm from the wiper motor assembly. If the arm is removed, the wiper arms may not park in the correct location.
   NOTE Use a suitable tool to separate the wiper linkage arm from the wiper mounting arm and pivot shaft assembly.
   
3. Remove the 3 bolts and the wiper motor.
   
   
   
   Fig. Wiper motor and linkage
   

To install:

1. Install wiper motor and bolts.
2. Tighten wiper motor bolts to 10 ft. lbs. (13 Nm).
3. Install windshield wiper mounting arm and pivot shaft.
4. Check wiper operation.

Rear Wiper Motor - Removal & Installation

1. Remove the rear pivot arm.
2. Remove the rear wiper motor shaft nut cover
3. Remove the rear wiper motor shaft nut.
4. Open the lift gate window.
5. Remove the rear wiper motor cover trim panel.
6. Disconnect the electrical connector.
7. Remove the 2 rear window wiper motor nuts
8. Remove the rear window wiper motor.
   
   
   Fig. Rear wiper motor view-2008 model shown, other years similar
   

To install:

1. Install rear wiper motor and tighten mounting nuts to 62 inch lbs. (7 Nm).
2. Reconnect the electrical connector.
3. Install wiper motor cover trim panel.
4. Install rear wiper pivot arm tighten nut to 53 inch lbs. (6 Nm).
5. Install shaft nut cover.
   
6. Check wiper operation.

Good luck (remember rated this post).

1. check the fuse to the rear wiper motor
2. check for power to rear wiper motor at the motor (power wire going in to the wiper motor with rear wiper switch on)
If you have good fuses & have power going in to the rear wiper motor...
3. Pull old rear wiper motor and install a new rear wiper motor.
Thank you please drive thru......

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

It,s a good possibility that the motor is bad, but first do this, turn on the rear wiper switch and go to the rear wiper motor and with a screwdriver handle tap on the motor body and see if it moves. Sometimes the brushes in the motor get stuck and tap on the motor body will loosen them up, also make sure you have power going to it.

Remove the rear pivot arm.
Lift the pivot arm to the upright position.
Slide the locking tab out.
Pull up and remove the pivot arm.
Remove the rear wiper motor shaft nut cover.
Remove the rear wiper motor shaft nut.
Remove the rear wiper motor cover.
Remove the rear wiper motor bracket nut.
Remove the bolt and the rear wiper motor.