Electric door lock failure on driver door - 2004 Jeep Grand Cherokee

Likely the most common cause is failure of the "electric plunger" inside the door.
It could be the wiring or the switch also, somewhere between the driver's door and the passenger door.
A good electrical tester may help you isolate the problem.
If it is the plunger, you'll need to remove the passenger door panel to access it.
God bless your efforts.

Check your door wire harness, wire is broken.
Check all four doors by removing the rubber case and retie wires with electrical tape or shrink tubing. Doors locks and Windows will work. It's a defect that Chrysler never own up to it with a recall. Wired are to short and break after awhile.

no. 10

Problem was caused by a broken wire inside drivers door panel.

bad master switch replace with new one

fuses are usually in the glove box or under the drivers dash or under the drivers side hood either physically inspect every fuse by pulling them one by one or the aid of a test light and a good ground to the test light

Failure of the Lock energiser. Take the Door trim Off, diconnect the Electric connector, Using a remote power supply connect that ,using the correct polarity, Pos to Pos....Neg to Neg, if you get no response, there is the problem.

Regards.DT

Any of these three causes may apply to your situation of your driver's rear door not power locking, specifically the malfunctioning of the 1) relay system, 2) switch motor, or 3) the switch/button itself. Here's a handy diagnostic article that explains this:
http://yourhandymanzone.com/Your_Handyman_Zone_How_To_Pages_Vehicle_Car_Zone_Cars_Trucks_Vans_Locks_Power_Locks_Do_Not_Lock_When_Pressing_Locking_Switch_Button.htm

This should lead you to the correction of your door's failure to lock.

Brad

I would follow their recommendation as I had the same problem with my car. They unhooked the power to that door and it was fine. The problem was a short in the wiring in the door that was causing the problem. So maybe get them to check the wiring in the door as well.