Another Power Lock ? Could really use some help!

I have a 1998 cherokee sport, with power locks and windows. Never had any problems, got to work, power locks worked fine.

Went out this evening to head home, power lock switch doesn't work. Power windows still work fine. I don't have any key fobs, so I usually open the driver's door with the key and hit the button to open the other doors. This evening, it didn't work.

Tried everything I could think of. Manually opened each lock on each door and the hatch - nothing. Tried to unlock/lock doors from the passenger side - still nothing. Tried it with the key out and key in the ingnition - nothing and even tried it with the car running - nothing.

When I hit the driver's door or passenger door lock button, you can hear a click at the switches, like it's trying to work, but doesn't.

Even replaced the 25 amp fuse with another and still nothing.

Is there a relay or module somewhere that operates the entire locking system, that I might check?

Could it be that one of the switches has gone bad and that keeps the other switches from working?

It seems funny that I haven't any problems at all and all of a sudden, all of the power locks quite working.

I'm not great at electrical problems, but I'm not that dumb either, but this one's got me stumped! :dunno:

Any help would be greatly appreciated, hate to take it to the dealer and really can't afford it anyway.

As always, thanks in advance! :yelclap:

Edit: I'm probably wrong about the driver's door circuit. We've got two threads on this now

ehall said:

All of the windows draw power from a 12-gauge wire in the driver's door, while the locks are on independent circuits. From what you describe, I suspect that the plug in the door just came loose. Did you use the spring clips when you put the panel back on?

Click to expand...

This may be discussed in detail if you search around, I don't know.

If you don't find anything, this is what I would do. The drivers door panel is the nervous system for the rest of the doors. If that switch dies, the whole system fails. The same can be said for the windows. If the fuses are in order, I'd try to replace the drivers door switch. A good test would be to jump the power lock terminals and see of they still operate. Throw a fuse on your jumper wire just to be safe. You can buy a little inline fuse at the local auto parts store for $3. It already has the wires on each end. If I recall, its the window switches that are all complicated, with the little circuit board and what not. The power lock switch should be simpler. You may be able to follow the wires from the drivers door lock actuator back to the switch.

One other issue that can happen is that the wires that run through the door can split over time. This happened with my speaker wire. On the other hand, the speaker wire is a very small gauge, and probably more likely to sever. If all else fails, I'd dig into the boot between the door and see how things look. You can remove the kick panel, unplug the harness, and pull it through the body. Here is a pic that illustrates what I'm referring to.

Click on image for full-size

Thanks for the reply!

That gives me a good idea what to check.

To throw a curve ball at the issue, got home, the car set for a couple of hours, went back out and now the locks work again!

I have a feeling that it may be the main power wire is shorting out, so that's what I think I check first.

Thanks again :sad1:

The wiring is kind of convoluted. Basically the lock switches trigger a relay, which then feeds power back to the selected actuator(s). The switches are on the same fuse circuit as the dome lights, the clock, and a few other things, so if those work that circuit is okay. The lock actuators are on a separate circuit that has a 30-amp breaker (I think) on the fuse panel. There are two relays for the actuators, one for lock and one for unlock (lock sends polarity one way, unlock sends it the other), which are under the passenger kick panel on my 91. The power feed for the relays is in the PDC under the hood, and is a 60-amp circuit breaker (I think).

The electrical FSM lays all this out pretty cleanly.

I am having the same problem in my 99 Cherokee. Power locks from the door switches click a relay in the passenger door and the Keyfob unlock turns on the lights on unlock and beeps the horn on lock. I will check the fuses, but I suspect that its one of those cables running through the hose in the door jams. I have had issues intermittently with all of the passenger window controls as well as speaker wires shorting out.

I had the exact same problem with my '00 XJ...the problem was a broken ground wire to the power switch unit. I had to tap a new ground wire from the switch hardness...through the door housing....through the flexible rubber conduit...and tapped it to another ground wire located on the driver side kick panel.