1996 Bonneville automated climate control prob

I have a 96 Bonneville with the digital climate control...my prob is that it has only shown 3 dashes ( - - -) instead of the temp and climate controls for sometime now. It blows air out the front defrost but thats it...and it seems to be the right temp , ie. cold air when its warm out and warm air when its cold out. Once in a while, usually after a DRASTIC OUTSIDE TEMP CHANGE IT WILL POP ON AND WORK NORMALLY.Then, if I turn the car off or after a little while, everything will disappear and those 3 dashes will appear again. I should note you cannot control anything on it when it has the dashes- rear defrost, temp, anything.. I got another unit, tried that and the same thing happened...any suggestions? Thanks!

After reading the diagnostic flow chart in my 93 manual, it seems that the control head and HVAC programmer are not communicating when the dashes appear. It goes on to say check fuses 11 & 17 but if yours works intermittently, I would say that they both are good. It might be a poor connection at the HVAC programmer. It is located above the passenger's hush panel. Look for any wires that might be partially pulled out of the connector. If it looks OK then disconnect and reconnect a couple of times. This has a sort of a cleaning effect on the pins and sockets. If this dosen't solve the problem, the next step in the flow chart says to hit the dealer and have them hook it up to the machine.

Since this information is obtained from a 93 manual, it should be very close to your vehicle but you should be cautious until it is verified by someone with a 96 service manual.