My drivers side door falls about a half inch whenever i open it what do i do to fix it

The bell will sound whenever a door switch is broken or its wiring is disconnected. Sometimes the door switches (which are located in the front of the door jamb, near the hinges) can fall inside because the plastic tab physically breaks off and then the system "thinks" the doors are open.

If the switches look secure, remove them from the doors, and with a voltmeter, check for a state change when pushing in on the switch with the wiring disconnected. No change, bad switch. If all four check OK, then the wiring to the door switches should be checked. The two primary connectors are underneath the driver's side bolster and passenger side kick panel. The lines terminate and connect here.

The wire that provides power to your door is split in half. This is caused by normal usage and results in lose of power when the door opens or closes and causes wire to twist which splits the two ends resulting in lose of power in only one location.
You can fix it by following the post by "grimmster" and "lane" on the following web forum (scroll to the middle of the forum to see their solution). This should only cost $10 bucks (need electrical tape; soldering iron and wire from Home Depot) rather than hundreds at the dealer:

http://forum.chryslerminivan.net/showthread.php/4555-02-T-amp-C-power-sliding-door-issue?p=49202

open the drivers door and pull back the boot that goes between door and body. all the wires run through it. you will find one or two wires in there that have broken in half. get a piece of wire the same gauge as the broken ones about 4 inches will do.put a crimp but connector on each end of the piece of wire then stripe and conect to each end of broken wire.loop the extra wire so it lays flat the loop keeps it from breaking again

window regulator has failed. Look for an after market one the GM replacement is junk. Usually it is a clip that holds the cable to run window up and down. probably a safety clip used if someone gets cought in the window, GM will charge you over $400 for the fix. not hard I have it down to about 30 min. and around $100 for the regulator.

I would have to think that it is in the window motor itself instead of the fuse. If the fuse was bad the window would not work at all. The mechanism that controls the window in the door is where I would start.

Sounds like the window regulator is malfunctioning. The vehicle should still be covered under the manufacturers warranty.

get it to the dealer asap.

you definitely need to take apart the door. There's something not right inside.

U need to replace the switch called a door ajar switch, it is defective and causing this problem, it is located in the front of the door opening it has a punger that moves in and out as door is open and closed. Here is a photo

could be a partially broken wire in the wiring harness that runs in the door track. the wires are inside what looks like a plastic chain that allows it to move with the door and have seen them partially break not allowing power to flow the whole time

Behind the door handle is a small plastic cover that has to be removed with a thin screw driver. Once this is removed there is a screw that can be removed. Once the screw is out, you will need to place a thin but strong putty knife into the crack at the bottom of the door and gently seperate the panel from the door metal. The plastic retainers are simply pushed into holes around the door frame.