Doors unlocking on their own

[Friday88]

The truck is a 1996 limited. I've noticed a feature that causes the doors to automatically unlock if the vehicle is in park while the engine is running, presumably to prevent locking the keys inside. But today this happened while in drive and moving down the road. No matter how many times I locked the doors, manually or by the button, the truck would automatically unlock all doors within a minute.

...any information on where I should look to solve this? I'm hoping it's simple lol

 

[NegroTundra]

Ive noticed that if someone is sitting shotgun with their arm on the window seal, and their arm pushes the lock down, my vehicle will do the same. This is usually on rough backcountry roads where their arm is coming into contact with the lock lever frequently. Weird for sure, but I just chock it up to a 20 year old vehicle with 230k miles on her.

Not sure on your issue, but if your trying to lock it frequently, maybe it sounds similar...?

 

[Friday88]

Ive noticed that if someone is sitting shotgun with their arm on the window seal, and their arm pushes the lock down, my vehicle will do the same. This is usually on rough backcountry roads where their arm is coming into contact with the lock lever frequently. Weird for sure, but I just chock it up to a 20 year old vehicle with 230k miles on her.

Not sure on your issue, but if your trying to lock it frequently, maybe it sounds similar...?

I've got about 240,000 miles on it, so it's not a surprise or anything, I just like to try and fix things if I can. I lock it every time I get into it though. I like to drive with the doors locked.

 

[Breadman03]

When electronics act strange, my first assumption is a ground issue. Not that I'm always right, but its a pretty solid first step to take.

 

[gamefreakgc]

Is the door position switch (little rubber button on the door jam) working correctly? It's just a switched ground but they do go bad from time to time.

 

[octanejunkie]

I had a similar thing happen to me in my 99 w/o keyless entry which turned out to be the driver's door lock cylinder not returning to neutral position (12:00) after using my key to get into the car.

A little graphite powder in the cylinder and some judicious key turning back and forth and now I'm conscious about what position it withdraw the key from the cylinder in the door, making sure to leave it at 12:00 (100% straight up) - since that, no more random locking/unlocking

YMMV

 

[Friday88]

Well I think it's something electrical. I just went out on my break to drive it, and I'm not getting any electrical power at all. I get the door ajar light and the ding, but nothing else runs or lights up. The power locks don't even move.

Normally I would assume the battery is flat, but I don't think this explains the lock behavior earlier. Also I have an Ultra Gauge that shows voltage and it's not been lower that 13.5. I have an alarm set to tell me if it drops below 13.

I'll try jumping it today and hopefully that takes care of it. Under the hood, wires that i can see all look intact.

 

[Weagle2]

My son's '96 Limited does the same thing and also unlocks overnight while parked occasionally.

 

[Friday88]

update

Alright we tried jumping it and it had no effect. Something has happened to the electrical system between the battery and the cabin. I really have no idea how to trace it back from the battery. I've never done work with this end of automotive electrical before.

 

[Tiktiki]

My truck (97 SR5) does the same when I hit the driver door interior with my knee (above speaker). I assume frayed wire somewhere in there...

In your case, take a look at the "big 3", that's most likely something that rusted/corroded/failed in there that is causing your power issues.

 

[gamefreakgc]

Well I think it's something electrical. I just went out on my break to drive it, and I'm not getting any electrical power at all. I get the door ajar light and the ding, but nothing else runs or lights up. The power locks don't even move.

Normally I would assume the battery is flat, but I don't think this explains the lock behavior earlier. Also I have an Ultra Gauge that shows voltage and it's not been lower that 13.5. I have an alarm set to tell me if it drops below 13.

I'll try jumping it today and hopefully that takes care of it. Under the hood, wires that i can see all look intact.

Check your interior fuses. That's the first place to start with any sort of interior power loss.

 

[Friday88]

Solved

My truck (97 SR5) does the same when I hit the driver door interior with my knee (above speaker). I assume frayed wire somewhere in there...

In your case, take a look at the "big 3", that's most likely something that rusted/corroded/failed in there that is causing your power issues.

Well it ended up being a loose wire at the battery terminal. The wire running from the terminal clamp to the fusebox had come slightly loose, just enough to lose connection but not enough to visually see it unless your checking. Reconnecting it brought power back and stopped the door unlocking issue.

I'm putting the "big 3" on my maintenance list now. All of these wires and connectors need to be replaced, and I've just been putting it off. Thanks for all the suggestions, hopefully this information helps somebody else sometime.