Door locks

[90Xjay]

I am still shaking down my 1990 XJ that I just bought and was wondering if any of you had the same problem with your electric door locks
This problem came with the Jeep from the car lot, so I don't have any history on it. The locks will lock but no unlock. They all seem hard to move manually, and I sprayed WD40 around the area of the doors that contact the striker plates and no difference. When I depress the switch to lock the dome lights go dim, so that indicates a direct short somewhere.
I think that maybe one of the servos is bad. Any tips on how to best track it down?
Thanks..

Mark

 

[MudderChuck]

I´ve had the same problem on every pre 91, XJ I´ve owned. I´ve WD-40´d the locking switch itself, the plastic door lock button, seemed stiff, seemed to help a little. A light graphit oil seemed to work best in the door latch assembly, didn´t help much.
Found a rubber anti rattle or spacer, twisted up on a front door lock rod, helped a bunch. The rears always seemed worse than the fronts.
Saw on another board where the voltage at the lock motor was measured and found to be quite a bit lower than battery voltage. The explanation given, was the number of splices in the power wire, various connectors, the small size of the wires and probably ground wires also. One XJ driver, said, he ran another bigger/seperate wire to his door/window master panel and added some grounds to the doors, said it really helped.
I don´t know exactly where the wires run for the door locks, under the door frame or under the drivers side carpet. I have seen on various XJ´s where the wires under the drivers side carpet, were chaffed and slightly grounding through moisture in the carpet padding to ground. I´ve also seen the screws holding the door jam (bottom) plastic on, screwed through the cable harness or skinning it a bit.
I´ve got more serious problem to deal with in my 88 at the moment, this coming summer I might work on the door lock motors some. I think I´m gonna start making sure the doors are grounded well, maybe add some grounds and work from there.
Speaking of grounds, the motor to firewall ground and the battery to motor ground, need cleaning and possible some star washers. An extra ground wire from the battery to the front radiator cross piece also helps. Made a world of difference in my XJ´s. After unhooking the battery, I´m gonna clean the power connections on the starter relay, mine look pretty corroded. Another XJ owner, said he added a ground from the alternator case to the battery negative pole, also helped with power some. Low voltage at various places, seems to be the sum of a little of this and a little of that, every little bit and extra ground helps some. Making sure the connectors, insides are dry, also helps, I´ve unplugged many with moisture inside.

 

[90Xjay]

It Won't Start!!!

Mudder.
Thanks for the info! I checked and sure enough, the new battery and terminal ends that the previous owner had installed left the chassis ground off. I promptly fixed that, and checked for the engine block ground also. I will test voltage at the lock servos, I just dred taking off all of those door panels, they can break so easy. I am also going to try running a battery charger while working the locks to see if more amps helps. then I will travel down that road awhile. That will have to wait a while longer, I need to track down a stuck damper door or vacuum leak for now cause the blower only works on defrost... Once I get this thing lined out, I think she'll be good to go. I just hate it when all of these little things dont work right.. gotta fixem.....

Best Regards,
Mark

 

[MudderChuck]

I don´t know if your XJ has AC or not, but on my wifes 87 (no AC) and at least one other I´ve seen. There is a cable mechanical actuator, to the defrost/foot warmer door (passenger side/under the dash). A push on type retainer, that pops off, the end of the cable just flops around, the default position (with the cable off) seems to be defrost. Also has a plug on top of the heater controls, under the radio. It looks like an electrical connector, but is actually like three vacume lines, that has come loose on occasion (can usually hear it hiss with the motor running). Had a cut line to the vacume resivoir, that seemed to mess with the heater controls also.
I´ve never had much trouble with the door panels, take my time and pry near the plastic clips with a large screw driver with feeling (don´t scratch the door). The arm rest needs to be rotated 90 degrees for removal on many models (which will drive you crazy if you don´t know). The door lock rods and inside handle rods, can be a pain, need a thin screwdriver and perhaps a pair of needle nose pliers, to unhook/hook the clips. There are some little retaining hooks, on the rear of the door/window toggle plugs, that sometimes fall off. There is a rubber spacer around the rods inside the door that can become twisted up and make the rods stick. The wind guard is easier to cut open at the door openings and duct tape closed, than to try and remove it around the edges. While your in there, smear as much of the window chain/cable as possible (there is a slot on the outside of the cable housing) with oil (motorcycle chain oil works well) or grease (hard to get to, but doable and necessary), Lubricate the window runners with a dry lubricant, teflon or graphit, grease the inside part of the door catches. Spray the inside part of the door lock mech with a light lubricant (WD-40)(grease gets thick in the cold and makes things worse). I can get a door panel off in about 5 minutes and on in maybe 8, done it a few (hundred) times.
Old XJ´s will keep you busy, I just unfroze and serviced the rear window wiper on mine, replaced the speakers and fixed a broken wire on a window motor.
The dome lights going dim, remind me of a problem I´ve seen before. Look under the drivers side carpet and inspect the wires that run there. I could be wrong, I´ve been working on XJ´s for years (like 15) sometimes things kinda get foggy. Frayed wires under the carpet, will eventually blow some fuses, pretty sure it was the dome light fuse. Could also be a bad ground, one is behind the drivers side kick panel (a pain to get off and on) another ground is the left side, under/bottom of the dash, near the courtesy light, tighten the screw and check for good contact. I´ve added a bunch of grounds over the years, most black wires are ground, splice in an extra wire and sheet metal screw to ground, solder works best to connect the wires.

 

[90Xjay]

Mudder.

I got all of my door locks to work!!!!!!!
Before I took and of the panels off, I checked the part of the visible lock that connects the striker rod of each door. I worked the locks manually (very stiff) and I found a small slot right next to the edge of the door panel, very hard to see, where a black plastic part of the mechanism moves up and down with the locks movment. This was very gummed up with old lube and debris. I shot WD40 in the area while moving the locks manually and it losened right up and got more free with each cycle. After repeating the step for each door, the locks work fine from the driver panel and each indivual lock. Something simple finally...

I also got my heater to blow out all other vents besides the defrost.
After about 1 hour of hard tracing, I found a bad vacuum hose on the engine side of the firewall. Funny thing, it goes from the fire wall(one side is pink and works the heater control valve for hot water to enter the heater core) the other one (black) with the leak, goes under the coolant tank, down the fender around the batter compartment and disappears through an opening behind the headlamp area???? Go figure..
I have not the slightest idea as to what a vaccum line would be doing there.
All I know is that I fixed the bad part and now the selector works.
YEEE HAAAAAAAAWWWWWWWWWWWWW.


Mark

 

[MudderChuck]

A few successes are always encouraging. I felt pretty good about getting my rear window wiper to work again.
That line you were tracing that dissappears under the battery, goes to the vacume resivoir, mounted behind the bumper on the right side. Had trouble with that line before.
I´m gonna try your solution to the sticky door locks and see if it doesn´t help mine also. Every little bit helps. I noticed mine seemed to work better with the motor running than when stopped. I played with the rods on one front door, bent it a little, so it didin´t rub, seemed to help a little. As did a lite oil on the lock button itself. Spraying the inside of the lock mech, with WD-40 also seemed to help some. It gets cold here, seems to make the locks worse, when it does (sticky?). Been dealing with the problem for 16-17 years, never did find a hundred percent cure. Always worse in the winter.
I´ve got an old XJ I´m stripping and junking, think I´m gonna take apart a lock motor/actuator and have a look see, just out of curiosity. The lithium grease in my rear window wiper motor, had the consistancy of white clay after 15 years or so, might look the same inside the lock actuator. Think like many small motors, in the XJ, they are french made. Like the window motors, the rear wiper motor etc. Seem to be some of the first parts to start acting up. maybe I can find some quality Mexican parts for replacement. :lol:

 

[Annihlator95]

I have a similar problem with the door locks, but only on the back doors...they lock very easily, but the unlocking takes about 5 tries before they fully unlock....do you think I should try WD-40ing the part that 90Xjay was talking about, or what?

 

[KellenNold]

Try WD40. All you have to do is remove the trim panel and there will be a little actuator that has a black rubber cover. It is located on the most rear part. Mine had your same problem and just shoot some WD40 on the metal piece that goes in there and I also pried up the boot and shot some down there. Works perfect now for 3 weeks.

 

[XJNick]

Here's something to think about: WD40 is a liquid. Most liquids conduct electricity. So it would probably be best to let the excess WD40 evaporate/run off before re-applying power to the power locks, if you suspect they are shorting out. :mrgreen:

-Nick :!:

 

[90Xjay]

KellenNold was right. After mine worked fine for about 1 week, I was back to the same problem, won't unlock and acts like it is shorting(dome light goes dim)
After a few minutes of different thinking, I found the real problem: The Pass side rear door actuator sticks. I lubed it best as I could under the boot. It worked fine for 2 weeks and stuck again. I opened and shut the door and it works again, each time it sticks I just pop the door panel or open and shut the door, to fix it for good, I will need to take it out and repair or replace it. I am still very happy to at least know the problem for sure. It works fine if I drive the Jeep every day or so, it onlysticks after about a week of sitting.

Mark