Reuzit47

digital message display sometimes irratic; displays flashing pixels and audible beeping; also HVAC controls irratic; one day they will work and the next few days or week they won't: anyone experienced this or have ideas to the cause?

Olds64

I did a quick Google search and found a place for you to start:

http://buickforums.com/forums/thread...t-2000-Lesabre

http://buickforums.com/forums/thread...ntrol-problems

The Buick LeSabre is essentially the same car as your Olds Regency. There are also videos on YouTube showing how to fix a similar problem with the display on these cars.

I would bet there is a bad solder on the circuit board of your display. I had a 2003 Ford F150 that had an inoperative compass and a flickering odometer. Both issues were fixed by resoldering surface mount resistors on the circuit board that had come loose due to a cold solder. Hopefully you have a soldering iron and know how to use it. It was pretty easy for me since I am an electronics technician.