Power windows were actually standard on the GT Celica and optional on the TA22 GTV Celica from Japan.

The front window mechanisms on my Celica are genuine TA22 for the GT. I was unable to find the matching rear set so I decided to get something similar to fit. I used window mechanisms from an RA44 with power windows. It was a time consuming job, but at the end of the day I got both sides working perfectly.

Below is what I did to get the RA44 mechanisms to fit into the rear of my TA22. I have my car stripped right down at the moment and it took me around 5 hours to do the drivers side. It was a bit of mucking around to get it perfect, but once I had it worked out the other side took less than an hour to modify.

This is one of the RA44 mechanisms when I got them.

First I removed the old manual mechanism from my Celica. Once out, I cut the main arm off so I could then reweld it back onto the RA44 mechanism. Once the arm is cut off (as shown below), the rest of the standard mechanism is simply rubbish.

Next I cut off the drive arms from the RA44 unit as shown below. These parts are not needed.

Be careful when removing the spring in the centre. It has a lot of energy in it and believe me, it bites hard when it's under load.

Once this was done, I then tack welded the original arm back onto the RA44 mechanism.

I used a large piece of cardboard to mark out the travel of the mechanism and bolt hole positions of my car to be sure it was spot on. As you can see below the flat connecting arm also had to be extended a bit for it to work properly.

 I didn't take a picture of it in the car because no mods were required to the original window glass or door panel.

It's great to finally have power windows in the rear of my car. I haven't done the front yet. I have original GT mechanisms for the front so obviously they will just go straight in.

I'm pretty confident that RA44 mechanisms like I used for the rear can also be modified to fit the front windows of any 71-77 Celica. The front doors are all the same for all Celica's between 71-77, so this mod would be the same for all models.