My heater is blowiing cold air HELLLPP

can't help ya i have the same problem with my 2000 pontaic bonneville SSEI , but it has dual climax control and the driver side blows warm and the passenger side blows cold , i think its a themostat at least i hope thats all it is ! any suggestions anyone?

Have you got Coolant in the Radiator? Low collant levels will cause cold hair to blow through the vents becuase there isn't enough warm coolant getting into your heater core. So it will just drag cold air in from outside. Check the Radiator before you start your car next. (DO NOT CHECK IT WHILE THE ENGINE IS WARM! or you'll be making a trip to the hospital ;) ) That, or your thermostat might be stuck... but on a car that new... I would hope not...

Definately sounds like a coolant transfer issue. Either no coolant or the thermostat is not working correctly. I would have the thermostat changed and the system flushed. Also, make sure they purge the system of air as this can cause engine overheats. I've also read on a couple of other message boards that the radiators fail often on these cars. I own a 300m and am going to change mine out due to a leak on the passenger side of the radiator.

I have a Chrysler 300M had the thermostat fixed on it,change coolant, put antifreeze in it and it still blows cold air what could it be other than those thanks

I got 99 Chrysler lhs the heater blowing cold air what's the problem you no

It's your cooling fans when they go out the hot air will turn cold. When you are driving the temp drops from the wind entering the radiator from the front grill of your car

low coolant causes no heat at idle or blockage in cooling system.

Just ran into the same problem with my 2004 300M, after installing a new battery. Online research reveals that it is probably the automatic temperature control actuator that is not opening the vents for the warm air to enter.

If your engine is equipped with an oil cooler with coolant lines running through it, it may be plugged or partially restricted. This is the lowest part of the cooling system and particles get caught in it. It’s located above the oil filter. Not expensive to replace ($125cad) and way cheaper than a heater core.

Just bought a used 2007 Chrysler 300, very very nice car. I noticed that when its hot outside the heater will blow out hot air even when the thermostat knob is off i have to turn on the AC to get it to stop blowing hot, but when its cold out the heater only blows out cold air. Someone said these cars ac and heat are all computer ran and the brain between the swich and door that opens for the heat is burned out. Not sure if thats right but it makes perfect sense.

If it blows hot on one side cold on the other it's a blend door actuator