Drivers door latch won't catch. most cold mornings when the latch doe's work i cant open the door

possible that the latch is already in the 1/2 closed position
put a round bar ( screw driver ) under the latch and pull the latch out as you press the handle as if opening the door

sometimes when it is this cold after car heats up and gets cold again the door mechanism ie latch can refreeze

Door latch on door itself is in closed position if it will not close at all. In this case, open door and pull outside handle hard to pop open door latch. If you have door opening at random, door latch needs replacing or door catch on body is loose.

IF DOOR WONT OPEN FROM INSIDE THEN IF YOU LIVE UP NORTH RUST IS PROBLEM.....TAKE A FUNNEL POUR BRAKE FLUID WHERE THE LATCH IS....WAIT 1-2 DAYS AND DOOR WILL OPEN.....SHORT TERM FIX

Door pins are a common failure on that series of Blazer/S10's. Also, another point of contention that the door faces is a sticky latch. Basically, the door latch re-latches itself and when you shut the door into the catch, it slams into it and bounces off. An easy fix is a 3 part cocktail of brake parts cleaner. Open and shut the latch with a screw driver acting as the catch and your interior door handle a few times. P'Blaster, open and shut the door a few times with the screwdriver acting as the catch. Finally, a good shot of white lithium grease. Open and shut the door with a screwdriver as the catch several times. Once you feel it is un-stuck, actually close and open the door several times. If you notice the door rising every time it catches, you MUST replace the door pins (cheap fix). If the door still has issues, replace the door latch (and since you're in there, do some PM and replace the actuator as well).

If it were me , I'd remove the inside door panel and take it from there. It may be that you can pry open the lock mechanism with a screw driver or a similar tool, allowing you to open the door - which obviously you must do. Even that, though, will not solve the cause of your problem. You may wind up at the dealer.

spray the latch catch with oil or silicone to loosen the latch mechanism than stick something [a screwdriver/ pen ] that u can use to push the catch upward to open push on catch while lifting handle if catch falls back either latch spring still frozen or latch spring broken and needs replacement

make sure the door handle on the outside has returned to normal position, sometimes the cold will make them stick. The door opens but the outside handle sticks open and the door won't latch. Hope this helps.

Look on the end of the door and you will see the slot where the door catch is located. It should line up with a big stud sticking out from the post by the drivers seat. The gap should be open. If you see a piece of steel blocking the slot, then the door catch is already in the latched position. Insert a screwdriver into the bottom of that catch and pull it up into the open position. If that is the problem, the door will work after that. Hope that helps

make sure the latch is open, use a screw driver, stick it in the middle of latch where the striker would latch the door, now open handle as if your opening the door hold handle in that position and pull screwdriver out slide away from door to open the latch,latch might have closed it self, try that first, hope this helps.