Andy's right...I have a 99 Xstar too and all the gages went out...the MDC unit was to blame. apparently water gets in the pickup lines, then after a freeze cracks the plastic near the MDC box and lets the water get into the unit
I think mine was around $180-$200.
When you install the new one, blow out the pickup lines with some compressed air and see if water comes out. Then hook up the speedo tubes to the unit.
Here you can see a coffee table covered with muddy water and a soaked paper towel full of the water once I cracked open the old unit. You can also see the corrosion that was taking place inside the unit.