Help! Heater/air Conditioner Instument Board Died.

[raz]

Need some help as to what may be wrong with my 1990 Lexus LS400 Heater/Air Conditioner instument panel. A little history first. about a year ago the radio stopped working. Lights remained on but no sound when I turned it on. I figured the amp blew. After a few months my heater/air wouldnt work when I pushed the on button. I checked all the fuses and everything was fine. I turned the car off and on again and suddenly the heater started working. Lights came on and back to normal for a week or two. Then it happened again. I turned the car off and on and it resoved my problem again. It wasnt long and the turning on and off the engine couldnt restart the climate control. So I drove it in the summer without heat or air. Periodically the heater/air conditioning would turn on when I started the vehicle. Does anyone have any ideas besides a fuse. I checked all the fuses. The under dash fuses and the fuses under the hood are all working. Help! Winters coming.