99 tahoe heat problems!

[dtaxtreme]

I just bought a 1999 tahoe today and 1 hour after buying none of the heat controls work fan knob works but only blows cold air on defrost can anyone help me out?

 

[SunlitComet]

perhaps your water valve is broke or it control line is disconnected.

 

[chauncey0337]

Or blend door actuator?