Passenger Power Lock issue (Locks but won't unlock)

[Karona]

Hello NICO members,

I have an issue that I can't seem to figure out through theory (trying to research the issue before actually taking off the door panel).
This is a December, 1998 QX4, never have been sure if that makes it a '99 or what, but it's all so similar that it likely doesn't matter..

The issue is as follows:
My right-rear door will not unlock electronically through the power lock switches. All other door locks are functioning correctly, they both unlock and lock with the switch, except for the right-rear door.

In order to open the door, I must reach through, and unlock it manually.. Now I have read numerous threads regarding power lock issues and the most common issue is that the power lock actuator may be damaged, or the wires going to it, etc. What has be most curious though is the fact that if I unlock the door manually, I can lock it using the power lock..

Does anyone has any recommendations or knowledge on the issue? It also turns out that that particular door has a look outside handle (I can wobble it quite a bit, but it's still functional, not sure if this could cause anything?)


Now this obviously isn't a major issue but unlocking it manually is quite the hassel so I would really love to fix this if possible, I have a lot of experience with electrical work, minimal experience with removing interior panels, I simply don't like the risk of snapping a clip, etc (this is a very old vehicle haha)

Thanks,
Kris

[atraudes]

Oh gnarly, I just read through the section on door locks in the FSM (page EL-191), and it looks like the door lock actuators work by having positive and negative voltage to them reversed to have the doors locked or unlocked. So, apply + to one terminal and - to the other, the door locks. Reverse it, and it unlocks! And you're right, from what I saw your setup is nearly identical to mine.

Based on what you describe, there doesn't seem to be anything wrong with the wiring up to the actuator, or it wouldn't lock or unlock. What I would do is pull the door panel off and inspect the linkage rods running to the lock and see if everything's in order. Then, unplug the electrical connector and hit the actuator with 12v from your battery, then flip the connections and try again. If it's in good shape it should lock and unlock as expected. Assuming all of the linkages are still in good shape, my guess is you just need a new actuator. Once you get the panel off, the actuator will be at the narrow part of the door right underneath the window.



Hooking up a multimeter to the disconnected wiring harness and confirming that you get flipped voltages when hitting lock/unlock would be a good idea too, though, for posterity's sake.

To get the door panel off, pop out the little circle in the grab area of the armrest, pull out the screw behind it, and pop off the armrest. Once that's off, you'll need to remove 2 or 3 screws behind it. When those are out, the bezel frame around the door handle will need to be popped off. Then, start prying around the edge of the panel on the bottom. Work your way around until you've popped all of the fasteners out. When it's good and loose, the panel will lift up and away. You'll probably break one or two clips (I did), just work slow and don't force anything and after you put everything back together you won't notice a difference. Worst comes to worst you'll buy a few replacement clips for a few bucks from the dealership.

Post back if any of that didn't make sense or if you run into any roadblocks, but let us know how it goes, regardless!

[Karona]

Thanks a lot for the instructions, like a fool I didn't actually look at the manual, I simply browsed forums endlessly haha...

I'll be sure to follow up once I check it out, bit of a busy weekend with Halloween and all, perhaps Sunday.

[atraudes]

lol no sweat. That's more than most people do