THE HEATER SWITCH WILL NOT GO OFF VENT TO DEFOG ...
1999 Chevrolet Blazer
The heater switch will not go off vent to defog or heater. Whats the problem?
Friday, February 1st, 2013 AT 1:21 PM
You can turn it but it won't change. Can you hear a hissing noise in the car on the right side or under the hood. It sounds like you may have a broken vacuum line, They generally break near the intake manifold due to being exposed to heat and they are just plastic