Power door locks on 89 cherokee

[slinker]

Hi, my car is an 89 cherokee laredo 4 door.

Each of the 4 doors and tailgate have differing levels of success when i hit the lock or unlock button on the driver or passenger door. One of the rear doors does not lock or unlock at all for either front doors control - window controls do work however. The tailgate seems to only respond to the passengers door lock controls. Is this a connection issue, or maybe a bad motor in the door that doesnt work?

Is taking a door apart very difficult? I mean actually removing the metal barrier to reach the inner workings of the door. It appears as if it would be fairly difficult and require some specially shaped screw driver bits...

Also in the off chance anyone reads this far - the rear door panels have an approximately 2" by 2" square cut in the carboard with screwholes to the side. It is located towards the bottom of the door and towards the front. There is no indication of this from the outside on the upholstery and nothing that i can see inside the door that would explain it. Is this for something that my model isnt equiped with, or something maybe originally planned but scrapped? Anyone know?

[Goatroper]

Can you hear the actuator move inside the door? If so, then the old grease has probably solidified and needs to be cleaned and then lubed with white lithium grease.

[kingslugnut]

My '88 has similar trouble. I've been through the actuators and latches. My current theory is that there is a bad connection. When I bench test a solenoid, the pull is strong and it draws 3-4A with a 6V input, a little more with 12V. When I meausre the voltage getting to the tailgate, it is just over 3V. If I disconnect one of the actuators, the voltage is enough to make the remaining four work properly.

Has anyone had a similar experience and might have a clue where the likely bad connection could be?

[JeEpBoY95]

my 95 had the same problem untill i opened up the door panels and gave it a good shot of WD-40 and now every door unlocks first try

[bre]

SAme problem here. Locks don't work very well. I have to do it a few times and it still will only open the pass door. Once in a while it will open the driver side and/or the rear latch. I've gotten to where I don't even try anymore, just do it manually.

[mansjeep]

Originally Posted by JeEpBoY95

my 95 had the same problem untill i opened up the door panels and gave it a good shot of WD-40 and now every door unlocks first try

Yeah, I also have the same problem. But I'm willing to try the above technique by Jeepboy95...

On the other hand, could it also be because I'm using a smaller-then-normal battery? The supposed batt for my 87 Limited is a 3m (or something like that) while what I have is only a 2M (which I plan to change). Could that be it?

[mansjeep]

Originally Posted by slinker

Hi, my car is an 89 cherokee laredo 4 door.

Each of the 4 doors and tailgate have differing levels of success when i hit the lock or unlock button on the driver or passenger door. One of the rear doors does not lock or unlock at all for either front doors control - window controls do work however. The tailgate seems to only respond to the passengers door lock controls. Is this a connection issue, or maybe a bad motor in the door that doesnt work?
.................

This is EXACTLY the case in my 87 Limited also! Wow... if you do find a fix (WD40 or otherwise) please inform me also... I'm having a Viper 350 alarm with remote keyless entry installed tomorrow and I don't know if I should proceed and if my power locks would cooperate with the Viper system. Thanks!

[ponchonutty]

It's hard to give an answer without looking at the vehicles in question but the most common problem I see is that the linkages get caught up in the cheap plastic that lines the doors then either just sticks to that or get bent to the point it won't work too well. The other is the lock mechanism, not motor gets gummed up inside. Another is the wiring involved either starts to fail like inside the door boots or something else like weak relays. Finally, the lock motors themselves. Sometimes the seem to check OK but might not be real strong because the motors are going to pot.

[Saudade]

This was the problem with my '88 Laredo nearly a year ago. I pulled the door panels and sprayed with WD40. All worked fine. Now it's starting again. This time I'll use grease. While you're in there, do the window tracks as well.

[mansjeep]

Got mine working already!!! And I didn't even have to pop open the door. I just used WD40 quite liberally (and tried to get into nooks as much as possible with the tube adapter) and viola! Apparently, the culprits in mine were the joints of the door locks themselves. Thanks!

[bill99hawk]

I had this problem. Fix this by wiring in two new relays that allowed all the locks to get full power. There seems to be a common problem with the 89 and models in that range with the power door locks. Here is a link to get you started on the fix:

http://www.naxja.org/forum/showthrea...ht=power+locks