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No heat in 2006 Dodge Grand Caravan

When my heat was on full blast, it would barely blow out, but it would be hot. I would have to slam the door hard or hit the dash to get the heat to blow out fully. Well the other day I was driving and the heat was on, but only cold air came out? I checked the antifreeze and it was empty (even though it was full a week before) so I filled it up and still no heat. I changed the thermostat (it is too cold outside for the car to overheat so I went off of a hunch) but I still had the same problem. I found a small leak under the radiator, and also when I disconnected the small valve fitted between a metal tube and a rubber tube, no fluid came out. Fluid should have leaked out when the valve was removed. I am going to replace the radiator, but I’m not sure if that is my heating problem because antifreeze still flows through it and the leak is very small. Any other suggestions? I’m not sure what to check on this type of vehicle.

Slamming a door to get air to blow from your heater indicates either a stuck blend door or bad contact to either the blower motor or resistor or the bad contact could be inside the blower motor.

Blowing cold air is a seperate problem and you have already found the cause, a coolant leak. When coolant leaks out, air comes in. Your heater core depends on the heat from hot cooland to transfer to the air that blows through the core. If you have air inside the heater core, it doesn’t carry enough energy to transfer enough heat to heat the air blowing through and coming out the heater.

Fix the leak or leaks and bleed the air out of the system and you will have heat.

The heating syatem in all water cooled cars works pretty much thes ame.

Thinking back to my 71 VW bus, air cooled systems are different, they don’t work at all:)