Heater problem

There are a couple things to start with checking but here is a guide that will get us started:

https://youtu.be/SNRb6pSwYuU

However, on your vehicle the blend door is cable operated so that is unlikely to be the issue.

This means we need to suspect the heater core is restricted so we need to check the temperature of the coolant hoses going to and from the heater core.

Please use a laser temperature meter to check them and here is a guide that will help with using this:

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

If the temps are not about the same and about the same as the other coolant lines, then we have a restriction, and the heater core will need to be replaced.

Let's start with this info and go from there.

Thanks