Here I document replacing parts for the front right power window to help anyone who might try. I did this for a 2017 g4 but I believe the process is similar for 2014-recent models.
The symptom is that it would make a spinning noise when controlled but the window would not move. Further, when pushed up manually, the window was easy to fall down. Some kids have played around with this window so that may be the cause of failure.
The process roughly is
Remove door panel
Pull out window motor and regulator assembly
Replace parts as needed
Reassembly
The parts used were
Phillips head screwdriver
T-25 (I believe) torx head bit attached to screwdriver or ratchet
10mm socket attached to ratchet. Deep wall is needed for one location.
Window regulator (if needed). I bought part #5713A318 from one of the Mitsubishi oem parts sites for $155
Window motor (if needed)
Utility knife is helpful
The time needed should be about 2 hours. I took much longer as I needed to go to store for tools.
To remove the door panel first needs 3 screws on the outside.
handle
Right side
Also 1 inside hand rest tray (not pictured)
After removing the screw inside the hand tray, the hand tray piece can be pulled. It is worthwhile to gently rock and pull it out, to avoid breaking any clips that secure the tray to the panel. There are cables attached to the hand tray piece that should be disconnected. It reveals 2 more screws to remove.
I removed this black piece near the rear view mirror, but broke off a piece doing so. Careful. I think next time I will try to slide it up first rather than pull towards me.
With 5 screws off the panel, the panel is almost ready to be pulled. The top side of the panel has plastic pieces that hook into the body metal. There are several of these along the top side of the panel. These pictures show these hooks when I already pulled them out, but they will start on the window side of the black metal.
What I did was place my hands on the top of the panel and bend the panel to pull the hooks out of the metal. I do this to avoid breaking them off the panel.
Also when removing the body, there are panel clips all along the perimeter of the panel that are pulled out when you pull the panel. Gently I rock the panel and pull towards me to release these clips from their holes.
I suggest not pulling the panel too much out at first, as these cables are still attached to the panel and come from within the body. These are for door lock and handle. The yellow and blue pieces can be pulled up out of the plastic that pinches them in place. Then the cords can be unhooked to release the panel.
The vapor barrier plastic I gently pulled off. These is a black goo sticking it to the door metal. Sometimes I used a utility knife to help cut the black tar to separate the vapor barrier from the metal. I bought replacement butyl rubber just in case, but I found the black goo was sticky enough to be reused when I put the vapor barrier back on.
I pushed the window down until I could access this 10mm screw on the right side of the window. It connects the window regulator to the glass. I took this off
There is 1 other 10mm screw that secures the glass to the regulator, on the left side. I had to push the window down a little to be able to access it through this hole. I needed a deep socket to access this screw.
With these 2 screws holding the window to the regulator gone, the window glass is free to move. I gently pulled the window up and placed it on a soft surface for later.
These 4 screws hold the window regulator and motor to the body metal. I used a 10mm socket on these. The red screw only needs to be broken, not removed
This is basically what the window regulator looks like hiding in the body. Note the 4 screw holes
There are 2 more 10mm screws toward the right side that secure the window regulator to the body, that I removed
This is where they would go on the regulator
With the 6 screws holding the window regulator to the body gone, the window regulator and motor can be pulled out. Also disconnect the cable to the motor. I used the hole in the bottom right to pull the assembly out.
Mine had much gunk.
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