2003 Chevrolet Silverado 1500 - HVAC messed up

I have a 2003 silveraldo 1500 I have air on one side and heat on the other

Probably a problem with the HVAC blend doors.

Tester

one of the blend door motors . . . your truck has two . . . has probably failed

Tell us which side isn’t working

One of the motors is easy to replace

the other . . . not so much