Q: I have found the correct part no. relay for the power door locks, but my manual doesn't say where is the relay actually located in the jeep. I have four relays behind the battery in the engine compartment, but those are not it. It doesn't have any relays on the fuse box.
A: They are located under the passenger side kick panel, under the dash. It takes a phillips #2 to remove the screws. What you have implied is that your door locks no longer work. The relays are usually not the problem, and replacing them hasn't helped too many others. The real problem is voltage drop from running the current from the passenger side switch, to the drivers, and back again to the relays. 8VDC is a common reading when it finally gets back around to the relays. It's just not enough. Some have gone through all the wiring and switches, cleaning every connection, and gotten improvement. But corrosion is just a wet carpet away from coming right back. There is a fixit on NAXJA that involves adding two more relays and direct power from the battery that just about guarantees no more problem - just search for "door lock fix." My door locks quit working two years ago, I'm gathering up the parts to add the extra relays, and the kick panel is sliding around in the back. Just gotta get to it.