Thanks to all the various posts, I have finally found the problem...the connector on the driver's side door lock was not seated correctly, so it would make and break contact simulating a key in the lock activating the pump!
This has been going on for years and many $'s later, it was a simple connector that just needed to be reseated.
I used this link to get the door panel off:
http://12.96.14.5/~engatwork/CkStrap.htm
The amazing thing was it only took about half hour...I have to wonder if the folks who replaced the pump (twice) will give my money back!