After a while, the mechanism (actuator) that unlocks and releases the rear glass hatch in
your Blazer or Jimmy will eventually burn out. when it does, there is really no way to open
the glass and lower the tailgate. The dash push button won't work, the rear key lock will
not work, the inside tailgate handle will not work, and you can not remove the interior
tailgate panel to access the mechanism because the screws can only be reach when
the tailgate is down (awesome GM design feature). The only way to replace the burnt
out actuator is to open the tailgate which you can't because the actuator is burnt out.
I've read stories that even the dealers don't know what to do, some have even cut up the
back panel to reach the so-called manual release. Others said they pulled back the glued
on carpet to search for it also.
Well if you don't want to hack up the tailgate panel or rip out your carpet,
here's the easy way to open the glass:
You just pull back the interior tailgate panel right above the bump in the middle
where the latch is. There are no screws or bolts in that area, you can safely pull it back
about 2 inches. Then you'll have to stuck your finger in and push down the release bar.
When you get your finger back there, you should be able to feel for the part that need to
be pushed down. When that part is pushed down, the glass has been unlocked.
Now that the glass is unlocked, it and the tailgate can be opened. Now you can remove the
interior tailgate panel, it has one screw on each side and easily lifts off.
The actuator that needs to be replaced costs $58 from the dealer, so if you don't want
to replace it yet, but still want to open the back, you can leave the panel off and just push the
manual release level.
I haven't replaced my actuator yet, still trying to find it for cheaper than the dealer wants,
but hardly any part store guys know what the hell an actuator is.