The door locks click on and off incessantly as the outside temerature climbs over 80 degrees. The emergency lights will also activate as the temperature rises. The dealer techinician was not able to find a short. Any ideas?

only a guess faulty
relays in the system just replace them

when the car is at the dealers I bet its under cover
and much cooler

activating relays must be shorting out internally when hot

I have the very same problem!
2000 Diamante, when it very hot it locks automatically when i close the door or touch the locks...and does not unlock in the same situations!

Where is the door lock relay located?

Its an issue with the driver side central locking controler , i have 2 cars that have had this issue my !997 Diamante VR-S and my 1990 Galant VR-4 . The Galant was alot worse, id lock the door or unlock and the dorr locks would cycle lock and unlock continnouslly til i would stick the key in and slightlly turn, but on the Galant as well as the Diamante i first sprayed WD-40 downward in the latch , and they both stopped after a hefty spray. The Galant did it one time a month ago and i just changed out the central lock switch on teh driver side door.