'99 cross country, tailgate opens and closes fine but the light on the dash stays on as if it's always open. Is this common problem and how can it be fixed?

thanks!

 

YES THIS IS COMMON. THERE ARE WIRES RUNNING UP THE SIDE OF YOUR LEFT HINGE ON
THE LIFT GATE . THE WIRES BRAKE AROUND THE HINGE AREA FROM MOVING ALL THE TIME .
IF THIS IS NOT YOUR PROBLEM IT MAY BE IN THE LATCH THERE IS A MICRO SWICH INSIDE THE
LATCH

 

The latch is almost always the problem with the light staying on.
If you replace it then here is a tip. When you have your next oil change DON'T let them lube it.

The lube in the door locks,latches is what burns up the microswitches.