Question on Electronic Climate control 91 Supreme
 

I have a 91 Olds Cutlass Supreme International series,it has the digital climate control also known as the electronic climate control as most of you guys already know. My problem is the head unit, at the moment I have it set on auto just to make sure that I can get heat. The display sometimes wont light up and the buttons wont respond. Other times the display works and the buttons wont then sometimes it all works. When I bought it the system cycled through air/heat and then through all of the settings, bi level, defrost, vents all on its own. I noticed that the rear defrost button turns on by its self from time to time as well. I don't know if this means I need to buy a new head unit or if there is something I can look for. The units are not cheap on ebay. Any help or suggestions would be greatly appreciated. Thanks!

I wonder if the wiring behind the unit has chaffed over the years and is now grounding, causing the buttons to be activated.