I have a 2000 gmc jimmy and the electrical release won't work.

SOURCE: can not oprn tail gate

Hello jhall 538...this is a common problem on the blazer. If you can hear the rod actuator working, then the actuator rod to latch rod connector has broken. It's plastic, and a poor GM design.
To get the rear hatch open you will need to manualy release it. It can be done by working as much of the plastic tailgate trim you can get loose, from around the top center of the gate, where the latch is. remove the 2 screws that hold the handle on and remove handle. Then pry as much as you need to access the c type latch, and release it by moving it... it's spring loaded and will only move one way. Haveing someone help you lift the hatch while you unlatch it from inside the vehicle helps. After you get the hatch up and the tailgate folded down, make sure the latch is locked in the open position.
The actuator can be repaired, i've done it several times. GM will try and sell you a complete new acutator, which is rather costly compared to the $8.00 piece of plastic you need. This is what it looks like...The little blue plastic piece on the end of the actuator is what you need.
Good luck and i hope this helps.

SOURCE: Tailgate latch will not release

Sounds like you have a bar disconnected inside the hatch. You may also need a latch itself. Does it lock and unlock? If it does, most likely a bar off issue. Will be a pain to get the cover off with the door closed, but you will need to remove it to inspect.

SOURCE: Rear Window Glass won't Release

what it seems to me is that your latch is stuck in a locked posiiton. If so, open the hatch itself to expose the screws in the inside panel. Once you have removed the screws the pry the bottom and sieds of the panel away from the body using a panel popper or flat screw driver. Then while applying upwards pressure to the panel from the bottom give the upper part of the panel a quick pop with the heel of your hand.. this should release the panel from the body, this will expose the latch itself. Using 10 millimeter socket, remove the latch from the body thus allowing you to remove it in a safe manner.

SOURCE: 89'S10 Blazer tailgate won't open

Thats what you will need to do is to remove the interior gate panel so you can release the latch. It will come off although a bit difficult with the gate closed, with a little care you can do it without breaking anything. It sounds like possibly a linkage retainer clip broke.
Try pushing in on the gate while turning the release handle in case the latch is in a bind if that dont work remove the panel

SOURCE: estate tailgate glass release button

to stop it from opening when you turn ign remove black cap from wiper swicth on the glass you see a circut strip cut the strip so it no longer works/ or replace £70 from Jagaur