Defroster not working

Hello,

It sounds like the mode actuator motor is not working which is a common failure. Here is a guide to walk you through the steps and the location of the actuator and ambient temperature sensor:

https://www.2carpros.com/articles/replace-blend-door-motor

You could have a vacuum leak under the hood that runs the HVAC system here is a guide to show you what to look for:

https://www.2carpros.com/articles/air-vents-stay-in-the-defrost-position

Check out the diagrams (below). Please let us know what you find. We are interested to see what it is.

Cheers, Ken

The temperature sensor for the inside is integrated into the blend door actuator. Look at the last diagrams in the post above. Also can you check the #1 actuator in the diagrams to see if it is moving?

Hers the outside air temp sensor picture again. It is located on the radiator side shield

You will need to remove the glove box door which will gain you room to get to the actuator. Upload pictures if you have trouble.

The ambient air temperature sensor is under the hood one near the hood latch. Here is a diagram to help. Check out the diagrams (below). Please let us know what happens.

Your car must not have one or someone cut the wires or took the sensor off because they say its in the same place no matter which engine you have.

I have seen the vacuum rotary valve at the HVAC control head go bad on these trucks causing the problem you are describing. Here is another location for the air temp sender next to the radiator. Make sure the system has full vacuum. Check out the diagrams (Below). Please let us know what happens.