Heater blend door location 1999 dodge dakota 3.9 litre

If you are circulating coolant thru your heater core and not blowing hot air out the vents, the issue has to be in the air box. The blend door must not be moving. I would think you are needing either the blend door actuator or blend door coupler changed.

it is inside the heater/ac box which goes from one side to the other under your dash and is a monster to get out. check to make sure your actuator motor (which operates the blend doors) is working first.

The blend air door is within the ac/heater box under dash

I am trying to locate the ac blend door actuator on my 2000 cadillac seville sts: AC blows air on the floor only instead of the dash board ac vents. Appreciate any help

Air Temperature Control Blend Door Failure No Heat or no AC (dependes on where door sticks)

In all modern cars there is a tiny DC electric motor driven gear drive that moves a plastic door that blends heated and cooled air from the AC and the heater core, this is called (interestedly enough) the air temperature control blend door actuator. The motor that moves this door fails because the door starts sticking from warping, most common complaint is no heat but it can be no AC as well. To replace these parts (blend door and blend door actuator) you must remove the entire dash from the car. Always have this problem confirmed by a dealer or qualified repair shop as it is a very expensive repair.

Other causes of no heat in the cabin are engine thermostats that are stuck open (engine runs cold) or air bubbles in the cooling system.

160 degrees should be hot enough to get some heat.
You could check the engine temp with a scanner to confirm.
I would double check the blend doors, and the temp of the coolant in and out of the heater core. I use an inferred temp gun.

Not. It is operated by an electric motor. But your problem may not be limited to the temp blend door motor. We also had problems with something in the heater box called a secondary stratification door. It works together with the blend door itself. Sometimes it would get warped and start hanging up. The solution is to replace the door with a revised door. It is also possible that you have an electrical problem in the heater blend door motor control circuit.The air mix door is malfunctioning or the controls are disconnected and allowing too much outside air to enter the cab. Sometimes you can get at the controls from the outside of the heater but you may have to open the heater to repair the mix door. Many times when cores are replaced the person forgets to reconnect the mix controls or breaks the connection unwittingly

its pretty simple remove 2 or 3 screws unplug it and remove,

have u checked the heater core inlet and outlet hose's are the hot, one hot side one cool indicates a plugged up core. if that is ok u may have a stuck air temperature control blend door in the dash air distribution system, also make sure your engine reaches at least 180 deg F.

normally if you take the two hoses coming out from the heater core you will find the heater control valve if it is under the hood and sometime they are in the truck on the passenger side down under the glove box