O.K. once again tell me how to get the rear hatch cover panel off to expose the rear wiper assembly?

Open the rear hatch. You must pull off the hatch panel. There you will see 2 bolts holding the motor in place. Remove the wiper arm and the nut under the cover first. Unplug the wires going to the motor. Then remove the 2 bolts to the wiper motor. Install motor with the bolts. Replug in the wires. Reinstall the hatch panel. Then you can reinstall the nut and cover. Reinstall wiper arm. Done.

Sorry, I don't have the data now..... but.Some hatches have a manual release on the inside. There might be a small plate near the door center that you can remove and open the hatch with a screwdriver.

but...I'm not sure tho about your car.

If the 2003 is like my 2002 Sienna and you are trying to replace the light within the hatch, then you have to access this light assembly through the rear interior panel. You can not remove the lens or the light assembly from the exterior of the vehicle. This really did take about 10 minutes.
Step 1 - remove the 2 screws from the hatch back handle by flipping the covers down to access the screws. Insert a screw driver about 1/16 of an inch into the top of each end of the handle to flip the covers down. This will expose the screws.
Step 2 - Use a socket drive wrench to remove the 10 mm screw from each end of the handle.
Step 3 - Use a screw driver to slide the cover up and off of the retaining clip on the left (drivers) side of the rear panel and remove the 10 mm screw from the clip.
Step 4 - Now the only thing holding the back interior panel on is about nine plastic clips. Carefully pull the panel away from the door starting at the bottom where the handle was removed. Work your way across the bottom and up the left side popping each of the snaps loose. Move back to the right and in my case the panel fell off in my hands. I was able to remove and replace the light with ease at this point.

Lamp, Rear Hi-Mount Lamp Assembly
Removal

1. Disconnect the battery ground cable (14301) .

1. Raise the liftgate.

1. Remove the liftgate door trim panel (46404) . Refer to Section 01-05 for the removal procedure.

Trim Panel, Liftgate Door Removal

1. Disconnect thebattery ground cable (14301) .

1. On vehicles with a rear window wiper, remove the three rear wiper motor cover screws and remove the rear wiper motor cover.

1. Pry the liftgate door trim panel (46404) away from the liftgate.

1. Disconnect the luggage compartment lamp electrical connector.
   
   
   
   

1. Remove the liftgate door trim panel

1. Rotate the rear hi-mount lamp socket counterclockwise and remove it from the rear hi-mount lamp (13A613) .
   
   
   
   

1. Remove the two rear hi-mount lamp housing nuts and remove the rear hi-mount lamp lens and housing.
   
   
   
   

Exploded view of the Explorer/Mountaineer rear liftgate trim panel (click for zoom)



Rear Window Wiper Motor

Fig. : Rear wiper motor assembly and related components

1. Disconnect the negative battery cable.
2. Remove the wiper arm and blade.
3. Remove the liftgate interior trim.
4. Remove the motor attaching bolts (3). Disconnect the electrical leads.
5. Remove the wiper motor from the vehicle.
   

To install:

1. Install the wiper motor in position and connect the electrical leads.
2. Install the liftgate trim. Connect the negative battery cable.

I hope helps (remember to rate this).

You need to remove the large plastic panel off the back interior of the hatch. 2 screws where the handle is and the rest are just plastic clips... Once this is removed you will see the motor assembly. About 80% of the people replace this motor, but it can be fixed. Take out the torx screws from the motor (after you taken it off the hatch) and soak the shaft the wiper sits on with penetrating oil. Work it free and put it back together, good as new. I did mine today, saved $100 from the wreckers. :) Good luck!

Remove the wiper blade by removing the plastic clip that covers the 10MM nut holding the wiper arm on. Just get hold of the very bottom of the clip & gently pull outwards & you'll be able to remove it completely.

Inside back hatch, remove the "hand hold" by just prying carefully. The 3/4" little plugs with an 1/8" area in the center-press on the center about 1/4" in and you can remove the entire plug. Just reset that prong you pushed in to the outside of the attaching plug & after installing, you press on it to lock it in place. Remove the 2 interior lights, simply use a nylon screwdriver to prevent scratches, or a regular screwdriver gently on the end away from the switch & pry gently, it will pop out-remove the wires noting the way they fit. Once all of those & the hand hole is removed, the panel more or less flips from the bottom where you removed the items, away from the bottom of the hatch. That will expose the wiper motor & since the outer arm has been removed, just unplug & remove the obvious bolts there & pull it out. good luck

1. Remove 2 plugs attaching liner to body to right/left of left/right light assembly. 2. Gently pull back liner to expose rear of light assembly. 3. Remove three 10mm nuts from exposed bolts. 4. Assembly now held in place by a plug in assembly that goes into a white plastic plug that extends into trunk under single bolt [See no. 3). 5. Pull to rear with wiggle movement to pull out plug. Takes a little while.

There should be screws around the edge of the panel. There are plastic panel locks that need to be pulled out, really the only way you can do that is to gently/firmly pull up on the panel. I had to exchange my rear wiper motor. To put the interior piece back on, just pop the locks back into place and screw back down.

You are probably correct in thinking its the wiper motor. You can do this but you will need to remove all the interior trim from the rear hatch first. Get a trim clip removal tool at a parts store...it will work much better than just a flat blade screwdriver. You'll have to remove the trim panels starting in order from the top of the door, then the left rear window side trim, then right rear window side trim, then the grab handle, and finally the main rear hatch trim panel. Once inside, removing and replacing the rear wiper motor is easy. You'll start by lifting the cover on the wiper arm retention nut. Remove this nut to get the wiper arm off, then remove the nut under neath which is the motor shaft mounting nut. Now, back inside to remove the other 3 motor mounting bolts. Don't forget to disconnect the connector for the motor wires. Reverse steps to replace.