The heater works really well except for it won't switch into w/shield defrost. It's electronic controls and I can change it into every mode and when I change it to defrost it shows on the display that it's working but nothing switches on and doesn't blow out of the front vents. Any ideas?

 

Oh yeah, on a 99 limited

 

No one has any ideas? I'd like to know if it's something easily done before I take it in.

 

Sounds like the heater control is going out....a very common, and rather spendy problem.

 

Heater control? Like the head unit or something inside of the dash?

 

Took the dash apart, checked the wiring all the vents everything looked fine... put it together and it started working again. I hope it keeps working and was just something simple. Thanks for tryin to help DC.

 

Sometimes just cleaning them out fixes them, but keep on eye on it in case it starts doing it again.