Door locks on a Saturn

I have a 93 Saturn SC2 (two door). It has electric door locks. On each door panel there’s a button. Push the button forward and both doors lock. Pull it back and both doors unlock.

A weird thing has been happening every now and then. I hear a grinding noise seemingly behind the little button panel for the electric door locks. It sounds like a servo turning (more like grinding…sometimes it sounds like plastic gears grinding). I usually hear it from both doors at once, but this last time or two, it seemed to come only from the passenger door.

The noise is not constant. It comes and goes in an erratic pattern. It seems to occur spontaneously. I can’t point to anything I do that triggers it. However, it does seem to begin when I turn on the key in the ignition. The pattern of noise continues when I turn the key off.

When this noise is being emitted, the electric door locks do not function. You can push the button forward and back on either door and no action takes place on the locks.

The erratic pattern of grinding noise continues for a minute or two, then subsides. Pressing the buttons does not seem to affect it (that is, make it stop once it’s begun, or cause it start if there’s gap of silence in the erratic pattern).

Once the noise finally subsides, the electric door locks do not function for the rest of the day. The next morning, everything works fine. (The last time this happened was first thing in the morning. When I got into my car that evening to drive home from work, the electric locks worked fine.)

The manual lock buttons always work OK.

Also, with this car, the external key lock on the driver door will unlock both doors (obviously engaging the electric lock function). But when this problem manifests, the key lock will only lock or unlock the driver door.

Any insights? What would cause this, and can I fix it myself?

I’d say you’re going to have to remove the inner door panel(s) and investigate. A service manual, such as Haynes, would be very helpful for a job like this. The manuals don’t cost much and they provide a wealth of information for the do-it-yourselfer.