No heat in my grand am

check the controller an vacuum lines

if NO heat comes out,have you checked to see if the flapper(door that opens to let heat out)opens or any obstructions????. Alberto

replace the panel control or heat control valve

white /light blue smoke is a sign of a blown head gasket or intake gasket when you changed the oil filter was it creamy cause if it was then is a head gasket

sounds like the thermostat is stuck open and needs replacing

it is the heater control panel. it is all electric. common problem with gm hvac controls

i have been having that same exact problem with my 2002 grand prix for over a year now, and when my ac is on the lower setting the it doesnt work plus the headlights and lights on my dash go out. On Max everything works. i changed the blower resistor(about $35), still doesnt work. i changed all relays and fuses related to the ac, still doesnt work. i changed out the actual ac control switch in the dash, still doesnt work. i have changed everything but the blower motor and have asked every mechanic and auto parts retailer i come across and no one knows the answer. The best answer i got is that it is probably a wiring problem like a short somewhere.

You have been told right. The resistor block is under $20.00 from the dealer.

Go to engine compartment, locate heater control valve. It will have the heater hoses connected to it that pass into the firewall. Unhook actuation plunger on the control valve. This will allow the coolant to flow though the heater core at all times. Now you have heat. If you get too hot, you can control it by the hot/cold settings to adjust the heater door.

doesnt sound good...i would have the body control module tested