Today, in the rain (I don't know if that matters), the "door is ajar" light came on while I was driving, and the locks started locking and unlocking by themselves over and over again. I pulled over and open and closed the doors. It stopped after that, and when I got home, I locked it up, and the car alarm would come on before I could get very far away from it. I had to leave the car unlocked. Later, I was going to unhook the battery to turn off the interior lights, but all of this had stopped happening. I locked it up, and now it seems to be fine. What is going on here, and what can I do about it?

 

Don't drive her in the rain! That's why my 90 hasn't ever seen rain in her 23 year life!

On a serious note, maybe the connections got wet and shorted? Have you checked the fuses yet?

 

I'd do a visual inspection of the door seal and the harness boot to the door at the hinge,. something got wet sounds like...Never did that until it rained? too much coincidence.
Until the time you CAN find a specific problem/cause, you can get some LPS silicone electrical spray and lube the switches and spray into the boot, door switches to displace any moisture and seal out future moisture. the silicone spray is recommended for the plastics and rubber of elec parts, where most petro based products will degrade certain plastics (like wire insulation) over time.
I am not sure, but if your car has a pcm or controller module in the door, that may be wet or the plug.

Corvettes have never been famous for being "high & dry" inside... in fact, I remember the theory that in the 89 or 90 that had rubber door switches THAT was the reason why! So when it leaked it didn't foul the window or door lock switch...

 

On your doors...at the latch area...you will see a black switch...one on each door. This switch is VERY IMPORTANT!!! And often times...on the door jamb where this switch contacts when the door is closed...the black push-in fastener has either broken off...or is at the point that the switch is hyper-sensitive and the black plastic push-in fastener can be carefully removed...and add a washer behind it and re-install it and check and see if the system works as designed. These switches can be replaced....but by using the washer as a shim...you will see if it fixes the issue first. I encounter this quite often on older cars and the switch(es) become "touchy".

(Ignition is NOT ON) When the door is open...your security light should flash on your dash showing that the security system is NOT armed.. When the door is closed ( and NOT using the power door lock switch) the security light will go off. Open the door and the security light flashes again. Then...with the door open..press your power door lock switch and you should see the security light STOP flashing and is STEADY on. NOW...the security system is armed. Close the door. Now the system will need the door key to unlock the door if you are on the outside and this will dis-arm the security. Also...when the door switches are working correctly....when the doors are shut...the interior light should go OFF in about 30 seconds. IF the interior light stay ON...look and see if the security light is flashing. If the security light is OFF and the interior light is on...this is another issue. which if needed...will be glad to aid you.

DUB

 

Thanks for the advise. Currently, it is still raining, and I don't own a garage. I think the flooding we are having here is even on the national news. Anyway, as soon as I am able to get out there and really take a look at the problem, I will get back with you guys!