Electric door locks spontaneously locking, and battery drainage

locks
doors
batteries
#1

I have a 1991 Toyota Camry that I inherited from my mom, that has been as trouble-free as one would expect. Sometime in (I think) August, the door locks became occasionally possessed, and would lock themselves, either just after I unlocked the doors with the key, or when I was sitting in the car. Then in late August, after behaving perfectly normally, it wouldn’t start; when the guy came to jump it, it started right up, though. A week ago, it was (apparently) dead in the morning, though the guy with the jumper cables said his diagnostic tool said the battery was ok. I drove it straight to my mechanic, who pronounced the battery past helping (it was about 3 years old, but I drive a lot for my job) and replaced it. And then yesterday, there it was, dead as a doornail, with the battery drained, according to the third guy who came to jump it (yes, I do have jumper cables, but I am afraid of frying my car, being a mechanico-dork). When I took it to the mechanic, I started to tell him about the door locks, but he shrugged it off. Does anyone know if the door lock thing indeed indicates, I don’t know, a short, or something, that could be causing this? Or is it just an artifact of some other problem – like now he’s going to tell me to replace the alternator (though he said a week ago that it was ok). I have always trusted this mechanic, who gets good ratings on the Car Talk site, too, but this is awful! Partly because he also just replaced the shocks, so now I have $1500 in this admittedly old car (156,000 miles on it) and I don’t want to keep putting money into it if it is time to sell it to some kid.

#2

The door lock problem may be causing the battery drain but I would suspect there may be something else causing that trouble. Your mechanic needs to check for an excessive current drain on the battery while the car is parked. He should know how to do that. The charging system should also be checked to see how it is performing.

The door lock problem is most likely due to a dirty switch and going from your statements I would suspect the switch inside the door that works with the key. Just cleaning the switch contacts may take care of that trouble.

#3

Thank you so much! I forgot to say that as of yesterday, for the first time, the front door passenger side lock not only locked itself but is staying locked - it won’t unlock with they key, the button, or the old-fashioned fingers-pulling-it up method. So far the other door locks aren’t doing quite that badly. I guess it makes sense that they would all get dirty at the same rate, though, huh?

#4

I would not sell it, but If I did not feel comfortable diagnosing the problem myself, I would pull off the inner door panels and unplug all the door lock actuators. That might solve your current drain, and it will keep you from locking yourself in the car and having to climb out a window. The fact that the passenger side won’t unlock when you pull the knob is really odd.

This car should go a lot more miles, but you may want to start settling for less than mechanical perfection (e.g. lock your doors manually)

$1500 is a lot to invest in an old car for shocks, but if the front is as much work to do as some cars I have owned, it is not unreasonable. I don’t know how hard it is to do on a Camry. Hopefully the car holds the road a lot better now? If not, then you didn’t really need them.

#5

The difference with the way the car rides is quite noticeable, so I am feeling pretty solid about that work being needed. I actually asked a (different) mechanic about whether the car needed new shocks about a year ago, and he said no – and was probably right, at that time! Sounds like a really good idea about just making the car lock manually in the future, too. I really prefer the kind of windows you roll down with a crank, not that they exist anymore (I imagine). Thanks for all your kind suggestions - I so appreciate it! Are you just a gracious car person out there in the ether? You don’t work at Car Talk?

#6

As a thought until you can get it looked at you might be able to see if other circuits on the doorlock circuit can be lived without and pull that fuse.

#7

If I recall correctly, this vintage Camry was recalled for the power door locks, and the only thing the dealers could do was remove the power door locks and convert them to manual. This was a very dangerous situation as these locks could activate and it would be impossible to open the door. The only way out was through a window.