It is probably a burned out bulb. The bulb is easy to change once you have the clock out. If I recall correctly you must remove the dash bezel to get to the clock on your Mystique.
The bulb with it's holder just twists into the back of the clock. Don't forget to transfer the green colored sleeve to the new bulb. The bulb is an usual size. I have not found a source for the bulb other than the dealer. It runs about $4.00 to $6.00.
