How to Repair a Car Door Latchby Chris Moore
The latch in your car door is essential to opening and closing it, no matter what make or model you have. If the latch isn't working properly, you have a very dangerous situation and need to repair it immediately. In most cases, you need to replace the latch altogether to repair the door, although you may find out that the problem is something else in the replacement process. Make sure you get a replacement latch made for your exact car.
Unplug the negative (black) cable from the car battery. You will be dealing with electrical connectors, so this is a needed precaution.
Disconnect the power controls and/or the window crank so they're not in the way of removing the door panel. Pry off the controls with a trim stick and disconnect their electrical connector. Use a hooked tool to detach the window crank's clip from inside the door, or rub a cloth in between the handle and the door to dislodge it.
Remove the car door's inner trim panel; disconnect its mounting screws with a screwdriver and lift it off its clips. On many models, the screws are behind smaller trim bezels on the door and pull handles; pry these panels off with the trim stick. You might also need to work the stick around the panel's edge to dislodge the clips. Peel back the watershield behind the panel.
Check that the actuator rods are connected to both the latch and the lock cylinder. If they aren't, this is likely the cause of the problem; connect the rods using their plastic clips and test the door.
Disconnect the actuator rods if they were already connected -- meaning they couldn't have been the problem -- or if you connected them and the door still has problems. If there is an electrical connector for the power locks, disconnect it as well.
Remove the bolts that hold the latch in place within the door. These bolts are on the outside edge of the door and require a Torx wrench on most vehicles. Remove the latch from the door through the access hole.
Install the new latch into the door, securing it with the bolts and connecting it to the handle and lock cylinder using the actuator rods. Reconnect the electrical connector to the power locks if needed.
Reconnect and assemble the door trim panel in the reverse order that you removed it. Reconnect the battery cable also.