2005 1500 4wd Z-71. I had to disconnect the negative cable from the battery to replace a fuel injector and after that when I run the a/c, the driver side blows cold air ok but the passenger side is blowing hot air no matter where the temp slide is located. No other connections were broken while working on the fuel injection system. Any ideas?

 

Sounds like the heater bypass door in the plenum is disconnected, jammed, or you may have a critter nest.