If the clock, temp etc screen is playing up & only showing sometimes it is due to faulty solder joints on the printed circuit board especially at resistors.
To access the unit Lever the vent panel gently from the dash board with a screwdriver, unclip the 2 wire
bundles & on a bench take out the display panel & take it apart being careful to keep the buttons in the vent frame. Pull the clock unit apart & access the printed circuit board. Re-solder the joints using good flued solder & use separate flux if necessary. It is difficult to make good joints to the PCB. Re-assemble & test in car by plugging in cables before fixing vent panel back in dash. Some companies provide this service Google car digital clock not working. Alternatively buy a new or second hand vent unit.
Wednesday, November 7th, 2012 AT 1:17 PM