A common problem on the WJ Jeep Grand Cherokee (1999-2004 models) is that power stops working to the all doors except the driver. This article details the most common cause and how to resolve it yourself.
Normally, when the problem becomes severe, you will find that you are unable to control the windows or door locks of all doors except the drivers. Some people report that the dome light will not turn off either, as the computer thinks the doors or open.
Generally, this problem gets gradually worse over time. It is common that the doors receive power when they are closed, but if the passenger door is open, then it will not lock until it is closed again.
These problems are caused by wires that have become hardened and break over time. The point of the break is usually within the rubber boot between the door and body.
Oddly enough, all other doors in the vehicle receive their power through the passenger door.
When performing electrical repairs on vehicles, always disconnect the negative battery terminal before starting work.
In order to repair the broken wire, the boot needs to be removed. This can be tricky, as the boot holds into the door pretty tightly. I find it easiest to remove by moving my finders around the outer edge several times, pulling little by little. There is also a plastic clip system beneath the boot. Once the rubber is lose, the clips have to be depressed through the rubber to be pull the unit out. You can only remove the boot from the door side, it is very difficult to remove from the chassis side of the boot, and I would not recommend it.
Once the wires are exposed, look for the orange wire. This wire is thicker than the rest, and is the one most common to break. In most cased, I find I can pull the wire out easily, as it is broken clean off. If you can see both sides of the wire break, then the repair involves simply getting a spare piece of wire, and joining the two back together using either wire nuts, or for the best job, soldering them and then sealing with heat shrink tubing.
If the break happened deeper into the boot, and you cannot see the broken end coming out of the chassis, then you will have to remove the pice of time from the inside of the vehicle, to the lower right of the passenger foot well. Once this piece of trim is removed, you can feel a bundle of wires going into the boot. You will need to remove the tape binding the wires together until you can see the orange wire. I find a pair of small pliers helps in getting a grip on the orange wire and pulling it into the chassis completely. Once you can access the broken end, you will need a new piece of wire of the same gauge. Most auto-part stores sell spare wire. Run the new piece of wire through the door boot, and on each end, join it to the orange wire using either wire-nuts or solder.
Take time to examine the remaining wires, to be sure no others have signs of stress from being pinched. If so, it might be a good idea to replace them while they are exposed.
Once repairs are complete, reseat the boot into the door, replace the trim if necessary, and reconnect the battery.