Power door lock problem on a 2002 chevy blazer...None of the buttons will lock or unlock the doors, and the rear gate will not open either. But when the truck is put into drive, all doors lock, and in park all the doors unlock. The fuse is fine.

 

Mine does the same thing, for like 6 months now

 

I'd bet it's something that is programmable.

Edit:
Check this

 

So does that mean I would have to take it to a dealership?

 

From the above link:
PROGRAMMABLE AUTOMATIC DOOR LOCKS (IF EQUIPPED)
If the vehicle has power door locks, it is equipped with a feature that enables you to program the power door locks.

The vehicle left the factory programmed to automatically lock all doors when the vehicle is shifted out of PARK (P), and all doors unlock when the vehicle is shifted into PARK (P).

If the vehicle has a manual transmission, it left the factory programmed to lock all doors when the vehicle speed is greater than 13 km/h (8 mph) for two seconds , and unlock all doors once the key is removed from the ignition.

The following instructions detail how to enter the programming mode for the power door lock feature:
Begin with the ignition in OFF. Then pull the turn signal/multifunction lever all the way toward you and hold it there while you perform the next step.
Turn the key to RUN and OFF twice. Then, with the key in OFF, release the turn signal/multifunction lever. Once you do this, you will hear the lock switch lock and unlock.
You are now ready to program the automatic door locks. Select one of the following four programming options and follow the instructions. You will have 30 seconds to complete programming. If you exceed the 30 second limit, The locks will automatically lock and unlock to indicate that you have left the program mode. If this occurs, repeat the procedure beginning with step 1. You can exit the program mode any time by turning the ignition to RUN. If the LOCK/UNLOCK switches are not pressed while in the programming mode, the current LOCK/UNLOCK mode will not be modified.
The following is a list of available programming options:
All doors lock/Only the driver's door unlocks: Press the lock side of the power door lock switch on the door panel once, and then the unlock side once.
All doors lock/All doors unlock: Press the lock side of the power door lock switch on the door panel once, and then the unlock side twice.
All doors lock/None of the doors unlock: Press the lock side of the power door lock switch on the door panel once, and then the unlock side three times.
No doors lock/None of the doors unlock: Press the lock side of the power door lock switch on the door panel twice. This turns off the automatic door lock feature.

 

There is a 3A fuse in the fuse block in the engine bay called "mir/lks", check that one. I've also read that the horn fuse will prevent them from working.

I had the exact same problem, replaced the "mir/lks" fuse, and I was golden. It might of popped if any or your door switch components are bad, causing an overload to the others. So if your power mirrors don't work, windows/etc.. it might cause it to keep popping.

 

I need a replacement power door lock switch for 1992 s10 blazer, driver's door. Any leads on where to find this switch?