Door Locks Going Wild

It is a 1998 Pontiac Montana.

Sometimes, the car decides to lock itself for no reason. I park in my driveway and hear the door lock lock over and over.

Sometimes when I am driving the car, the doors lock over and over.

Sometimes when I am driving, and turn on the right blinker, the doors lock with each blink of the right blinkers.

I can't get any of these conditions to repeat themselves, but they do happen on a regular basis.

Any suggestions on tracking this one down?

....It is a 1998 Pontiac Montana.....Any suggestions on tracking this one down?

Yep,

I have a few. If you have an afternoon, take the step plates off of both front door sills and look for any water or water damage to the wiring harnesses you find there.

The normal way the water damage occurs is when the tray on the air conditioner backs up inside the vehicle and the water finds its way into the channel on either side of the van; - usually the driver's side.

The other way water can enter the cabin is through a poorly sealed windshield (from the top center of the windshield). The water that enters follows the windshield channel and down the 'A' pillar to the channel on either side of the van.

My guess is that there is enough corrosion or water present to cause certain wiring circuits to become activated (depending on whether the ignition is on or off), or when the water sloshes or the attitude of the vehicle changes.

Worth a look...:eek:

I don't see any step plates. I was testing it out this afternoon when it was being goofy. When the right blinker blinks, the doors lock. When I turn on the emergency flashers, the doors lock (with each blink). The brake pedal and left turn signals do not cause the doors to lock.

....I don't see any step plates....

First, the step plates are those plastic pieces that your feet drag across as you enter the van from the driver's side or the passenger side. They cover up a small amount of carpet too and run from the front of the door opening to the back of the door opening.

You may not be able to see them because they aren't jumping up to smack you in the face! (humor) :banghead: My 17-year old son has the same problem, "Dad...where's the....?"

What you are describing are unrelated parts of the van causing things to happen that shouldn't (normally). These are all symptoms of a crossed up wiring harness or even a poor or non-existent ground somewhere.

Electricity will find a way to ground even when a ground path that should be working is not or simply does not exist. Imagine for a minute that when your signal lights are on the wiring is finding a way to ground through the power locks. :shakehead The wires under the plastic step plate may in fact be your problem.

I don't know, it might be in the steering column perhaps because many of the wires that service locks, signals and so on get power from the ignition lock, but it wouldn't hurt to pull the steps up, look for water or corroded wires or connectors and go from there. Why pull the column apart unnecessarily.
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