2004 grand marquis blowing cool air cant get hot air why?
Check the horn - if it doesn't blow, then you may have found the culprit. In most cars, the lighter and horn are on the same circuit.
replace heater core and or themostat Coolant level may be low not allowing hot coolant to circulate properly, check coolant level.
Fuse is blown.
Take the car to a service center which is equipped for this. You must be careful how much you put in or you will blow the system...........Then you pay.
Most likely the bad news that you did not want to hear. The heater core is leaking coolant.
You got a short somewhere. Might be in the wiring, might be in the element itself. Either that, or you're overloading it.
Check to insure that the engine coolant is full and the thermostat is not stuck. Without the heated fluid from the engine the heater will always blow cold air.
possibly blown head gasket
Short in the wiring or a bad horn switch.