Truck not getting to proper temperature

When you say your temperature gauge is reading low, what exactly is it reading? Can you get a picture of it and tell me what you approximate ambient temp is?

If you are only getting cool air then I would agree based on what you have replaced, the actuator seems like the issue.

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

Let me know about the temperature gauge and we can go from there. It may be worth while to get an infrared temperature gauge and check temperature around the engine and see what it is running at just as a baseline.

https://www.2carpros.com/articles/how-to-use-an-infrared-temperature-meter

Hi,

Can you tell me if both hear core hoses are getting hot when the engine has been running and the heater has been on? If they are, then I would suspect the blend air door isn't working. Take a look through this link:

https://www.2carpros.com/articles/car-heater-not-working

If I remember, the heater control is actuated by engine vacuum on these. Have you confirmed vacuum to the vacuum control motor on the air plenum chamber? See picture 1.

Let me know.
Joe

If hoses are both hot, then the problem is in the vehicle. Check the vacuum motor I mentioned and make sure it is getting vacuum and working.

As far as the temperature, I would check to make sure the coolant temperature sensor is in good condition, the wiring isn't damaged, and the plug isn't loose or corroded where it makes contact. I attached a picture of the sensor location.

As far as the reading you get in the vehicle, I would suggest getting your hands on a infrared thermometer. Allow the engine to warm up and check the coolant in the radiator. It should be close to 195° F. It will cool in the radiator, but it should be close.

Let me know.

Joe