1991 Honda Accord Wagon

You park your car next to another Honda which was moved from the other coast.

or...

Poltergeists...

Did you ever do a search? You may have to read some, but.............................

Problems With Power Door Locks on a 1991 Honda Accord SE | eHow

1994 Honda Accord lx door lock control module fix - Honda-TechCivic door won't open from inside or outside FIX (no drilling ...Power door lock problem - Honda-Tech1998 Accord power locks problem - Honda-Tech1991 Accord Problems - Honda Accord Forum - Honda Accord ... How does the rear window washer work now?

Probably either a bad unlock button or faulty wiring to the button.

Maybe your car is trying to escape an abusive owner by inviting theft...? ...on the other hand it could be the door lock actuator....

http://www.jcwhitney.com/1991-2007-honda-accord/door-lock-actuator/p3038905d855y1991-2007j1.jcwx

http://repairpal.com/faulty-door-lock-actuator-may-cause-power-door-locks-to-activate-intermittently-049

Are you accidentally activating the unlock button when you put the keys in your pocket?

Sometimes it's the simplest things.

I had a similar experience with my Park Avenue and it was a fuse that was shorting out.

Actually, I should have explained it better...my door locks were locking and unlocking as I was driving. Yes, I thought my car was possessed. But, then, I had a lot of strange experiences with that car! There was one issue I experienced with the trunk....it wouldn't stay closed after I opened it. (Yes, sometimes I'm a blonde!) When I first bought it..brand new...the entire car started to smell fishy inside.The humidity had increased as it was October and getting closer to winter (in Phoenix?). This stopped after they switched out the headliner, which was glued with a fish-smelling glue. The first three months that I owned it, paid cash, of course (don't ever do that!), the car was in the shop more than I drove it!

<...What could be causing this?...>

One of the possibilities is a reluctance to scrap the vehicle.

Your comment is why our society is overloaded with garbage dumps and the chemical poisoning of our land from manufacturing processes. Kudos to the guy with the 1991 vehicle. Our "throw away" society is killing us all.

yeah, my 1972 Jeep gets 6 miles to the gallon and there ain't nothin' wrong with it!

well, it leaks a little...about a quart a month, both oil and transmission fluid...each

...and a little brake fluid...

But hey! Kudos to me!!! I ain't poisoning anybody with a 90% recyclable resource!

</sarcasm>

Sometimes it's best to get rid of old technology, as it creates more pollution and damages our environment. A 1991 (even a Honda) will have some fluid leak, not to mention the higher tailpipe emissions. Did you know that Honda Accords have been P-ZEV since the mid 90's here in California. Our skies are much clearer since I moved here in 1987.

Try pulling out the fuse that supplies the central locking circuit, and use the door key properly to open and close the door?