2004 Pontiac bonneville 6 cylinder, no heat..blower works

Double check your coolant level and make sure yo are not reading "low". If OK and you have had the cooling system drained recently, you may have air in it that needs to be purged. Does you heater core get hot? If it does, then you probably have a blockage in the core itself or an actuator in the air tubes is not functioning. if it does not, check the flow through the radiator all the way back to the thermostat.

I’m new to this so I appreciate your help. I have hot pipes going in and out of fire wall. Thus I would say heater core is hot. The vane isn’t moving to let the hot air to circulate. Her car has some fuses out..they burn out again when replaced. So I suspect those fuses OR the vane control. Thus I was looking for the fuse that controls this function and then upstream the actuator of vane movement. I don’t suspect a anti freeze blockage or thermostat. I think it is the vane actuator or the fuse system controlling it, which I can’t figure out is what fuse. Thanks..so appreciative of your help.

Old timers cheap trick - Start pulling all fuses one by one and replace each with a new fuse. It will only cost about $10-$15 and will either tell you the new fuse fixed the problem or the new fuse will blow but you have found the problem circuit. This will require you to turn the car on and then pull the new fuse to visually inspect for failure..