You may have to resolder the circuit board on the back side of your instrument panel. The story goes that the expansion / contraction of the circuit board from heat and cold cause the solder joints to go bad. You have to remove the instrument panel from the car, and then remove the screws in back to separate the assembly. Then you just resolder the joints where they attach to the board. Worked well for me and my '86 325. There used to be a good site that explained this exactly. I can't get the page to come up now though. You may be able to find some more info if you surf around. Good Luck. Houston