Dash doesn't work in wet or cold weather
 

Hi. I have an audi a6 2002. I have a problem that when the weather is wet or cold my dash won't work. Well the monitor that shows problems works and while the car is not running the miles and clock readings are working, but when the car starts it stops working. Also when this happens speedometer isn't working either, as well as every other thing like gass and oil temperature. But when the car is running for a while, it seems that as the engine warms up the dash begins to flash, also every other light start to flash, like button lights and then everything turns on and works normaly. Do you have any ideas what is might be the problem.