2005 Chevy Silverado 1500 5.3L: Passenger AC/heater vents blows hot

Hi,

Sounds like the Blender motor door actuator for the passenger side is stuck in the Heat position.

The actuator is located behind the dash between the radio and the airbag towards the firewall. To replace it,

you would have to literally remove the complete dash and disconnect passenger side air bag in order to replace. You definitely want to avoid using the Dorman actuator and try to replace with OEM quality. I have had to replace the Dorman brand actuator twice in a year; luckily it is in an accessible area.

If just one side blows hot then check the blend door. Should be under dash on passenger side. First you should try to reset it by turning ac on and turning both dials all the way up to 90 and wait for it to get warm, should take 30 seconds and then turn them both back to 60. Do this about 3 times and it should reset it. If that doesn't fix it then check fuses.