the Heater and A/C Controls are not lighting up or showing that they are working at all with the exception of the fan speed switch which appears to change the speed or at least work on high. The only Air is minimal coming out of the Windshield vents, and appears to not even be changing temp. deffintely is not getting hot. Really cold right now would like to know if anybody may now why it started doing this all of a sudden. All controls were working fine on way to work yesterday. Thanks.

1500HD silverado 2001 70,000 miles.

Just went out and checked it again, now all controls appear to be working. Any ideas or has anyone experienced this before. Is it something I should make sure and take care of now. Truck is under extended warranty, but deductible is around $100. This again is the first time this has ever happened since owning truck.