I have an electric rear window in my tailgate that won't go back.

the outside latch and other parts https://www.google.com/search?q=1989+chevy+blazer+s10+tailgate+latch+assembly&rlz=1C1CHBF_enUS812US812&source=univ&tbm=shop&tbo=u&sa=X&ved=0ahUKEwjnvKX9tu_iAhVth-AKHYMBCpcQsxgILw&biw=1600&bih=789 https://www.youtube.com/watch?v=E0yC1-EhjSI

there's a plastic actuator inside the tailgate that probably broke or at least came loose. You have to crawl into the back and release it. I ended up having to cut a little piece of carpet in the middle on the top of the tailgate area. Right where it fastens. You can manually release the glass with a screwdriver at that point. To replace the actuator, you need to take off the entire tailgate trim and metal underneath that to get to it. It sounds like a pain but trust me, not having the back glass be able to open or the tailgate area is much worse. It takes about 45 minutes to fix. The actuators are less than $10

i have the same problem...there is a release switch inside of the talegate that has a lever on it that pushes the rear window release. on mine the tip was broke on the lever. take the plate off and you'll see what i'm talking about..

If you can hear it then you don't have a fuze problem. More than likely it can be fixed by adjusting the catch in the tailgate. Open you hatch with the key and lower the tailgate. Remove the tailgate interior panel/cover and you'll see the catch for the window. Adjust the catch a little, tighten it up, raise the tailgate and close the hatch. Try your release on the dash again and see if this fixes the problem. You may have to repeat this a couple of times until you get it adjusted to where it needs to be. If this works, then reinstall the tailgate interior panel and you're all done.

http://www.carforum.net/general-auto-repair/7310-2003-chevy-blazer-door-lock-rear-window.html

I don't know what wrong with your tailgate but your engine is a 4.3 liter

your going to have to remove it from the inside, remove as many screws as you can that hold the panel on, then pry panel open until you can reach linkage to pop window and then linkage to open rear gate. good luck.

under the carpet installed on the tailgate door, there is a hole. put a screw driver in it and manually flip the latch open, to start.
yjen take the door panel off, one screw with the interiro handle, and pull the rest off,
watch the auto release slidw side to side, you will find a broken piece here, I made an extension piece with a plastic hook and screw, works fine for over a year, lube all latch parts with wd 30 once opened.

IF YOU get in the back the panel will have a slot behind the carpet this will be in center right at top of carpet area on plastic panel pull carpet back and you can slide a screwdriver in there and move actuator to open

latch the locks and trick the door in thinking it is shut. then once you are done pull the handle and relase the latches before you close the door.

there is a safty switch in the latches that keep the window from working unless the door is shut.