Passenger side heater blowing cold air?

Hi,

It sounds like you have a faulty blend air door actuator. This actuator is what controls the temperature entering the passenger compartment. Since you have heat on the driver's side, we know the heater core is good. So, the actuator on the passenger side is my first suspect.

I attached the directions for replacing the actuator below. What I suggest is to remove it and while it is still connected, see if it responds when you change the temperature request on the passenger side. If it doesn't, it's either bad or there is no power to it. You can check for power using a test light.

https://www.2carpros.com/articles/how-to-use-a-test-light-circuit-tester

Also, here is a link that explains how, in general, one is replaced. You may find it helpful as well.

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

Let me know what you find or if you have other questions.

Take care,

Joe

See pics below.