• NAXJA is having its 18th annual March Membership Drive!!!
    Everyone who joins or renews during March will be entered into a drawing!
    More Information - Join/Renew
  • Welcome to the new NAXJA Forum! If your password does not work, please use "Forgot your password?" link on the log-in page. Please feel free to reach out to [email protected] if we can provide any assistance.

97+ power locks

OoerictoO

NAXJA Forum User
Location
PDX
i've been trying to debug my locks for years. i finally tore down the hatch, unplugged the actuator, hoping it was that one, the cheapest.
door locks still don't work. i get that click in the PDM.

so i unplugged the passenger front door lock actuator/latch thing. power door locks then work. great! so i replace the passenger front actuator/latch from a used ebay unit that was supposedly a "working pull".

when i first put it in, all the door locks worked. an hour later they would lock but not unlock. now they are as before, just the click in the PDM.

question is thus: do i try another door? or try another passenger front actuator?
or is there some known way to overhaul/lube/clean the actuators in these latches?

thanks!
 
Make sure that your linkages aren't bent. They are easy to bend when removing the door handles. The power locks phyically move the linkages that connect to the manual lock/unlock button (not the switch). When bent, the toggle button doesn't work well and the electric actuator doesn't function.

In addition to that a little plastic gear inside the actuator strips out. I servicing an old unit a few years back and it's a lost cause. If you get a used unit, it will eventually die. They start to make a whining noise when they are beginning to go.
 
Clean the lock cylinders and the door latch mechanisms. Use throttle body cleaner. Lubricate everything with Break Free CLP gun oil. Google CLP gun oils. WD-40 is neither a cleaner nor a lubricant and it dries to a sticky/gummy film.

While you are in there working, as suggested, make sure the operating rods are properly engaged and not bent.

Also, carefully hand inspect the wires in the door and door hinge area. Look for any damaged wires, separated wire splices, and for chafed wire insulation.
 
I've got a related issue for 2001 Cherokee 4 door.
Door locks wont do anything, but I could hear them try to do something when plugging a battery back in.
After some exhaustive troubleshooting with the service manual, I discovered that the [UNLOCK] wire (PK/BLK) to all 5 door lock actuators is hot 12v all the time.
Has anyone experienced that before? Where did you find your short?
 
Failure of the drivers door and tailgate wire harnesses is very common. If all the wires check out and test as good, consider that the drivers door master switch has failed. If the Cherokee has remote keyless entry, disconnect the RKE module temporarily to eliminate a faulty module as the root cause.

Carefully visually inspect and wire continuity test the wires in the drivers door hinge and tailgate hinge area. Look for any damaged wires, separated wire splices, and for chafed wire insulation.

Clean the lock cylinders and the door latch mechanisms.


.
standard.jpg
 
Last edited:
Make sure that your linkages aren't bent. They are easy to bend when removing the door handles. The power locks phyically move the linkages that connect to the manual lock/unlock button (not the switch). When bent, the toggle button doesn't work well and the electric actuator doesn't function.

In addition to that a little plastic gear inside the actuator strips out. I servicing an old unit a few years back and it's a lost cause. If you get a used unit, it will eventually die. They start to make a whining noise when they are beginning to go.

I had this issue too. I took out the mechanism from one XJ to another, and the door worked, at least in manual mode. I cleaned the unit and regreased. I did notice the original unit had a bent rod. Straightend it and it worked. So, I don't know if the cleaning helped or if it was the bent rod.
 
So this Auto Lock issue is really making me tear my hair out. I have torn apart both the drivers and passenger door harnesses and unwrapped them.
The door harnesses are fine.
Same with the back hatch. I unplugged the harness, cut the boot, pulled it out and unwrapped it.
The back hatch harness was fine.
All the Pink/Black servo wires (unlock circuit) are still getting a constant 12v. I've unplugged them all so see if there was a stuck/shorted servo. No joy.

I unplugged a lot of things in the electrical system to try to isolate it. I can isolate it by:
A. pulling Junction Block Fuse #15 (Passenger Power Lock Window Switch)
B. Pulling Junction Block Connector C2
C. Pulling Power Distribution Center Large Fuse #4 (50 amp, Power)

The ACC 12v (Tan Wire) does not isoloate the problem.

I have gone through the entire Shop Manual Troubleshooting process and have not traced down the issue.

Does anyone have a handy guide of appropriate voltages for each pin at the Junction Block? Or continuity chart for the various pins at the junction block?
 
Constant 12 volts to the door lock circuit seems normal to me because you can lock/unlock with the ignition key out.

Clean the lock cylinders and the door latch mechanisms. Use throttle body cleaner. Lubricate everything with Break Free CLP gun oil. Google CLP gun oils. WD-40 is neither a cleaner nor a lubricant and it dries to a sticky/gummy film.

Unplug the Remote Key-less Entry Module.

One at a time unplug each door, check for symptoms, and plug back in.

Failure of the drivers door master switch module is common. Some functions are controlled/coordinated by the passenger side module. Failure of the passenger door switch module is somewhat common.
 
Tim MN, 12v red power to the passenger switch is normal, and correct, but constant 12 v to the unlock circuit can't be normal. It's got constant 12v at the servo. That's only supposed to be powered when you click a switch. It means the auto locks are constantly struggling to unlock. Therefor they can't be locked, even manually.
I have confirmed this by removing power from the lock circuit by pulling fuse #15, locking all the doors, and then replacing the #15 fuse. The doors all immediately unlock. When I unplug the servos and manually apply 12 to either side, they will lock or unlock appropriately.
There is nothing malfunctioning about the lock servos. they are all doing what they are told. It's just that they are constantly being commanded to unlock.

I have already gone through the troubleshooting steps you mentioned, and the entire troubleshooting guide in Chapter 8P of the shop manual.

I'm very confident that the door harnesses are not the issue. I have tested for continuity between the various door harness wires and there isn't any. i have unwrapped the harnesses and inspected them visually for any chaffing or damage. There wasn't any. Same with the hatch.

The autolock portion of the manual, Chapter 8P, is handy for troubleshooting a failed component, but not finding a wire short.
The electrical portion of the manual, CHAPTER 8W, is great for identifying a particular wire pin, but not very helpful for troubleshooting a wire short.
I suspect that my electrical problem is either in the harness behind the dash between the drivers side and passenger side, or between the junction block and the PDS forward of the firewall. Either of those scenarios would require ripping out the dash to unwrap the main harness. I'm trying to minimize the carnage.

Again, is anyone aware of a chart of truth values for individual pins at the junction block? Volts, Amps, Ohms? That would help me figure out which individual wire or circuit is the outlier.
 
If the Cherokee has remote keyless entry, disconnect the RKE module temporarily to eliminate a faulty module as the root cause.

Have you opened and inspected the drivers door master switch ? I have a couple spares so I just swap in another as a diagnostic test.

Wiring issues are very common as is switch failure. If the wires in the doors/tailgate are good, I would suspect the switch.
 
They way I understand it is that the passenger side switch controls the locks.
My '00 since day one the locks would work 98% of the time.
When they did not work it would only be for a short period of time.
Like I would go into a store, they would not work, come out 15 minutes later and they did.
One time it was for 3 days though.
When they don't work I can still hear a click coming from the passenger side door.
Gave me the impression that it was not wiring.
So awhile back having extra parts I threw in a used passenger side switch.
Lasted a month before they did not work one day.
Immediately swapped in another used switch.
That was over a year ago and has been fine since.
Not really sure I solved the problem but........ LOL.
 
Back
Top