A/C blowing cold passenger side hot on driver side

[JakeStone]

My 2003 Silverado 5.3 is blowing cold air through the passenger vents but hot air through the driver side. I replaced the blend door actuator in hopes that the manual climate control had gone and that’s why drivers side was only blowing hot but the Dorman actuator from O’Reilly’s didn’t solve the problem. Any and all suggestions are appreciated it’s starting to get hot in Vegas! 

[grandpalarry777]

You might want to watch a video from the South Main Auto Repair you tube channel. He describes your situation and a possible repair instead of replacing your heater core.