How do you test heater control valve 2000 ford f150 5.4?
If the core appears to be OK, the next concern is with the blend door that diverts air through the heater core. This is a common failure on the F150. We have a video posted on our web site that shows how to diagnose and repair the system. Please follow my user name back to my bio page to find a cut-and-paste link to the web site. You are only a few clicks away from solving the problems.