So I have an '87 Jeep Wagoneer XJ that I love to tinker with dearly. I've already replaced the two front door lock actuators and am working on replacing the weatherstripping, et al. for the rear doors now. I had all the out yesterday for refurbishment and decided to see look at the actuator, since it hasn't worked (it clunks, but doesn't move the lock) since I bought the jeep. I thought maybe the grease in the lock mechanism itself was causing the problem, but even after a thorough cleaning it still didn't work (btw, it was about frozen from the old dried grease, but after soaking for several hours in my heated/agitated ORIGINAL Pinesol solution and a re-greasing it's moving easily again!).

It turns out the actuator itself is just too damn weak. I previously pulled apart my front door actuators and there really isn't much to these devices...basically a 12v motor and rack/pinion to move the arm. Why the heck do these things fail? If the motor itself is moving one can deduce that it's not an electrical failure. I can understand if the grease dries that you get increased resistance too, but once that was cleaned up I expected that it would lock, but still no. If I remove the arm from the actuator it fully functions, but apparently it's just too weak to function properly. Can these things be overhauled or are we just kind of stuck with buying new ones?

This post is more just general curiosity...I'm happy to buy some more I suppose, but I just prefer to rebuild when I can.

ps: one thing to note is that I have *not* done the relay modification to ensure 12v to the rear doors...it's on "the list". So I know that I may not have 12v to the rear.

 

Planned obsolescence

 

Sounds like you're pretty familiar with the mechanics of electrical motors and whatnot... it's pretty common for a motor with brushes and armature to become weak over time (I have a ceiling fan in my garage that used to blow you away on high... 18 years of duty and you're lucky to get a "medium" speed out of it).

I too like to rebuild things and salvage what I can. The general consensus from long-time users on here - even the gurus long-versed in professional mechanical knowledge - is to buy replacements.

 

Well shucks...

but thank you for the reply!

 

Glad to help.... nice waggy ya got there, btw!

 

If you could try powering the actuator directly from the battery or a 12V power source that would be interesting. You should actually be seeing closer to 14.2V with the engine running actually.

I've taken one of the actuators apart because I thought it failed but it turned out to be the door latch that was all gummed up. Either the factory grease or whatever previous owner's had been spraying turned into thick tar. Combine that with colder weather in the winter and it was actually hard to unlock/lock the doors manually.

I cleaned the door latch assembly in a varsol tank and lubricated the mechanism with silicone spray. White lithium grease at all the pivot points of the linkage between the actuator and latch and the manual lock/unlock. All of my old door lock actuators worked right away once I'd cleaned everything up.

I would highly doubt that the brushes would have worn out in the motors. They barely see any rotation just to spin the drive to get the actuator to extend/retract. My bet would be on you not getting full 12V or a huge voltage drop under load to your actuators.

 

That is a good theory, but he said he already tested the latch/lock mechanism by hand and it moved freely.

 

Have a similar problem on my 89. locks are sticky. Seem to work fine in the summer but intermittent when the cool weather rolls around. Even unlocking the lock switch manually take some effort - which I suspect speaks to things being gummed up.

 

Took a look inside one of the doors today to specifically free the lock up. Sprayed everything in side/in sight with lubricant but it didn't have much effect. I think my battery is a bit low so I've got it on the charger.

 

Good luck bud. I've got a brand new 700CA battery with a full charge and it still doesn't budge 'em

 

Sometimes just cleaning the motor up fixes them. Clean the brushes & holders, polish the commutator, lightly oil the bushings.