1996 Camry Driver Door-Open Switch or Sensor

[jdave5917]

The switch or sensor that detects when the dirver door is opened and then sends the signal to turn off the headlights and turn on the courtesy dome light is working erratically. Coincidentally or otherwise, this started to happen right after I had some paintless dent repair done on the driver's door panel, and all of the dents were in the vicinity of the door lock. Unfortunatley, it started to work the again next day and worked for about two weeks until I got stuck with a dead battery because I turned off the engine and exitied the car in daylight and didn't notice that the headlights were still on.
Since I had to replace the inside door handle on the driver's door anyhow, I decided to look for a loose connection or weak ground, etc. inside that door. After about 6 hours, the door handle was fixed but I was not able to find and correct the door-open sensor malfunction problem.
I think I've narrowed the problem down to the door lock mechanism in the door that grasps onto the metal bar mounted on the door jamb and hold that door shut. If I open the door and the dome light doesn't come on (indicating that the swith or sensor has not been activated), I can get the switch/sensor to trigger the dome-light-on and headlights-off functions by bringing the door to an almost fully closed position (the saftey latch has caught but the door is not fully closed) and shifting the door a little. I tried to duplicate this by manually moving the lockiing mechanisn in the door from the open to the locked position and back agan, but that doesn't seem to do anything.
Does anyone know what actually senses that the front door has been opened? Is it a switch that is part of the electric door lock mechanism, or is there a metal-metal contact circuit that is either closed or opened?
Either as a coincidence or perhaps related to all of this, the exterior lights no longer flash when teh security system is activated and deactivated. This occurred around the same time
I suppose Isuspect that would correct the problem , I hate to do trial and error with expensoive parts. I'm hoping that someone else has experienced a similar problem and found an sure/easier (and less expensive) solution.

[dc_98_cam]

The Gen 3 wiring diagram ...you can download from top of forum page .... shows that the front LH door unlock detection switch is contained within the door lock motor unit. ... p.161.
The wire that goes between the detection unlock switch and the door lock control is light blue with a red stripe. ...If you can visually trace and inspect this wire, you might find a break or maybe some bare insulation .... Also, a frequent problem appears to be broken or bare wires in the door hinge area ... which require opening the rubber boot to be able to discover them.

The diagram also shows a white wire with a black stripe going from the door lock motor unit to ground ..... probably check this also.

[jdave5917]

Thanks. I probably should have removed the elecric lock motor while I was in there so that I could get a better look at everything. I checked all the wires as best I could using a light and mirror, but there could still be a wire that was nicked during the paintless dent repair, or perhaps a part that was removed and a bolt or screw not tightened completely when it was reassembled.
I just noticed that part of my post got cut off where I was saying that I suspect I could correct the problem by replacing the door lock motor, which apparently also contains the door open detection switch according to the wiring diagram that your referrenced. That's what I was referring to when I was saying that trial and error can be expensive when it comes to electrical problems.
It seems like there may be a spring that is part of the door locking mechanism that helps move the door latch that grasps the bar on the door jamb. I say that because there appears to be a spring-assisted resistance when I atempt to move the latch mechanism manually. I'm thinking maybe the spring is getting weak, or more likely that something is binding and the spring is not strong enough to overcome the resistance of the friction forces.
I'll have get back to it when I have some time to kill, and in the meantime try to remember to always make sure the headlights are turned off when I exit the vehicle.
Worse than leaving the headlights on -- as my wife was leaving work the other day, she disarmed the security system, opened the driver's door and started the engine, and then closed the door while she scrapped the snow off the windows. Since the door-open switch wasn't activated, the security system didn't realize the car was entered and it reset the security system and relocked all doors while she was outside the car -- with the keys in the ignition, the engine running, the snow falling and the wind howling. That caused me to get a nasty call (why don't you just take this thing to someone that knows what they are doing??) and a request to come rescue her.

[Mike Gerber]

Try this quick and easy fix. The switch and screw in the door can become rusty on the backside and can cause problems like this. With the driver's door open, lift up the rubber cover from the bottom of the switch. This will expose a bolt (I believe it is 10MM). Remove the bolt and pull the switch out just a bit without disconnecting it. Now clean all the rust off the back side of the switch and also the spring and the shaft the spring rides on. It has a tendancy to get very rusty on the back side of that switch. Use a wire brush if one is available. Make everything as clean and shiny as possible. Also clean the bolt itself. Clean the threads and the underside of the bolt head. The bolt grounds the switch to the door. Now cover everything with dielectric grease to prevent the rust from returning. Reinstall the switch and see if the problem is solved. This should take about 5-10 minutes.

Mike

[jdave5917]

Wow - thanks for that bit of information. I never noticed that piece and would have assumed that it was simply a rubber absorption bumper for when the door closes.
I assumed that the problem had to be with the wiring inside the door somewhere since this all began when I brought it home from the paintless dent repair.
I'm sure your correct that the problem is with that switch. Knowing that that is the switch, at least I can manually duplicate the problem, and will know when I get it fixed.
I'll do as you suggested and get back to you with a confirmation.
thanks much!

[jdave5917]

Originally Posted by Mike Gerber

Try this quick and easy fix. The switch and screw in the door can become rusty on the backside and can cause problems like this. With the driver's door open, lift up the rubber cover from the bottom of the switch. This will expose a bolt (I believe it is 10MM). Remove the bolt and pull the switch out just a bit without disconnecting it. Now clean all the rust off the back side of the switch and also the spring and the shaft the spring rides on. It has a tendancy to get very rusty on the back side of that switch. Use a wire brush if one is available. Make everything as clean and shiny as possible. Also clean the bolt itself. Clean the threads and the underside of the bolt head. The bolt grounds the switch to the door. Now cover everything with dielectric grease to prevent the rust from returning. Reinstall the switch and see if the problem is solved. This should take about 5-10 minutes.

Mike

Thanks Mike - it didn't look corroded when I removed it, but I cleaned everything anyhow and added the dielectric grease before reassembling. I cycled the door about 25 times without a failure, so that had to be the problem.

[Mike Gerber]

Glad it fixed the problem for you. Remember, it might also have been the bolt itself. The bolt threads ground the switch to the door frame.

Mike