My van is overheating and the heater is not blowing hot air.

Yeah, the blend door covering the heater core to let the warm air come in is still mostly covering the core because the vacuum line is ether off the door actuator or the actuator is faulty. Check to see if it's getting vacuum to the actuator first with the lever on full heat.

Check the coolant level.

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This might sound like too simple a solution, but after owning 5 expeditions, I think I may have an idea.

It is possible that the cooling system is simply not full of fluid. If, when changing the thermostat twice and other service, the system was not sufficiently bled or burped, this can happen. What happens is that people do these repairs, and then fill the radiator, but fail to completely flush the cooling system. My son had the exact same problem on his Mazda 3 (Mazda was owned by Ford then), and flushing his cooling system solved his problem.

Think of it this way: If your heater works fine, then goes cold, that usually means the heater coils which the air blows over have no hot fluid in them. As for overheating, your thermostat opens when your engine reaches a certain temperature with the intent to exchange the too-hot fluid with water cooled by the radiator, but if there is only air, or insufficient fluid in the engine after the exchange, you will overheat.

Ask your mechanic to flush/burp the cooling system completely. I hope this works.

Hi,It sounds as though the radiator is blocked.the heater might be opening letting in hot air which will over ride the cool air.

This is usually caused by air in the cooling system. While the engine is cool, check your fluid level in the coolant tank. Then check the radiator to make sure it is full. If both of them are full, the system has to be bled. To bleed the system, take the radiator cap off, start the engine. If there is air in the system it will bubble out and the fluid level will drop, add coolant until this stops.

check the heater core and the fluid levels

1st you need to make sure no air in your system open you radaiator cap and your heater to max and see if air bubles or circulation is going on fill up accordingly otherwise you have blockage in your system or water pump if no circulation ////make sure no bubles all bubles should be gone////look for coolant circulation in your radiator make sure your thermostat is not defective or placed in the right position.

Probably one of two things. First make sure that your coolant level is full. If the coolant is not flowing properly you won't get heat. If you begin to get heat while driving, but only when you are excelerating, this is your problem. If that is not it you may need to change the thermostat. This is noot hard as long as it is easy to get to and it should be easy.

did you check the fluid level by removing the rad. cap? Radiator should be full to top. If Chryslers are low on coolant, the heater will not blow warm air.

Sounds like you may have a partially plugged heater core. You could flush this out separately, from flushing radiator & engine block. Diconnect heater hoses going to your heater core and clamp off, so not to loose coolant from engine. Now hook up separate hose to one side of heater core pipe and flush out with typical garden hose. Repeat procedure on both heater core inlets. Reconnect original heater hoses and test difference. You may have to add an additional litre of antifreeze. If this don't work i suggest changing heater core. Good luck.........Ron.