My 2000 528i seems to have a mind of its own sometimes. Twice (incidents a year apart) after the car has been sitting outside in very hot conditions (100 degrees), the whole instrument panel goes black and the A/C does not work. The blower blows, but no cold air comes out. The instrument panel will come back on sporadically for a few seconds. The last time this happened, we were on a 7 hour drive in hot weather and had about 15 minutes of A/C for the whole trip. When the instrument panel goes out, the clock does not keep time, nor do miles accumulate on the odometer. We were on the way to the BMW dealer the next day when just on a hunch I pushed the odometer button with the car off (as you would to check the mileage), then when I started the car everything worked fine and has continued to work fine. Was this a coincidence? Anyone have any ideas? We were out of town and I called my BMW mechanic, but he had no thoughts on why this would happen.
My first check would be the power source to that area. There seems to be an intermittent connection somewhere. The problem may be in the main connector to the dash. Possibly, this problem could be fixed just by disconnecting and reconnecting the connector to the dash.
Given the complexity of the electrical system it’s no wonder your BMW mechanic had no thoughts
In your BMW the cluster is the meeting place for all that is on the bus, and then you have module upon module to deal with.
It’s problems like your having that doom a originally very good and expensive car to having very dimished re-sale value.
My bet is the cluster itself,then the General Module,then wiring.