[TGARST]

I friend of mine had the same problem with the HVAC control on his 98 Park Ave. The fix is easy, remove the HVAC control and replace the lamps with Radio Shack Micro lamp PN 7219. The light bulbs in the park ave had a Blue rubber cover on them, use a razor blade to cut them off and reuse. All of the lights where burnt on the HVAC now it works great and has been okay for 2 months. You will need a small wattage Iron and a solider sucker to remove the old bulbs.
Good luck
Tim