1992 Town & Country with electric locks. No remote locking/unlocking that I am aware of (I never had a key fob for it).

My locks normally lock when I hit about 18 miles an hour, and stay locked until I am done driving and unlock them. Yesterday however, as I was coming home from work (about 55 mph on the highway), they unlocked and relocked, and several minutes later, un/relocked in rapid succession maybe 20 or so times, very spastic like.

What might be causing this? What bits are normally responsible for the automatic locking of the locks?

 

It maybe one of the door ajar switch, The most common one is the sliding door. Remove the switch or replace it and try driving it again.

 

So far it's only done it that one time. I've driven it back and forth a couple of days since with no issues. Maybe some moisture got in somewhere? I'll keep an eye on it though, and if it happens again I will check the door switches.

 

I had the same issue while driving. It seemed to happen after a hard rain. One day the locks were sporadically locking and unlocking while van was off in the driveway.

The alternator was replaced prior so I hadn't thought about an electrical issue. I took it to the dealer and they flashed the computer, but the locks did their thing again a week later.

Just on a whim, I changed the van's battery. Voila! No more spaztic locks!

My main fear was it happening when I was on the outside with doors closed and kids in car.

Hope this fixes your problem!

Bee