Help with Buzzer and Defrost switch

At any given time for any amount of time when im driving there is a buzzer that goes off for no reason. It is not the seatbelt buzzer. There are no warning lights that come on. It is driving me crazy. Does anyone have a clue to what this may be coming from??? Also, my rear defrost switch works sometimes and sometimes it doesn’t. It seems that the colder it gets the less it wants to work. After the car is good and warm inside it usually works. Is this the switch in need of a good cleaning or something else???

Probably need to clean and adjust the contacts? Check the teg tips for that.

I am having the same trouble…
Also intermittent wipers don’t work.
With the help of a Chilton’s manual, I believe the problem is the “Integrated Control Unit” which is located behind the fuse panel (based on the source of the beep). It controls the rear defrost, intermittent wipers, key in beeper, and some other things.

Pulling the fuse panel seems kind of risky. Anyone tried to change this unit?