the blend door actuater is more than likely the cause of the noise.....very common....can go in behind the glove box to replace it.
The heater blower for a 2002 Chevy Silverado is mounted under the dash. It is on the passenger side, in the heater housing.
the heater fan resister,it is or should be on inside or on outside heater box.
The heater inlet hose is on the firewall. On the 2002 Silverado it is close to the bottom of the firewall on the passenger side.
10000.00
If it is a gas engine, then no. If its not gas then yes.
Check your coolant. Is it thick and gunky?
Nope.
maybe the heater core.
High Miles
Your heater relay switch may be bad
Broken line at the heater core possibly
The coolant level is low in the truck.