Heater on 2005 chevy silverado 1500 ls

Shop. It sounds like your mode door actuator is shorted. If in fact there is a problem with this actuator, most times the mechanic will have to remove the dashboard in its entirety to replace the faulty component. Good luck.

There are 3 actuators one near the floor close the transmission hump. That one controls air flow to the floor and when activated it will revert air to floor or to the top of dash. The other two are behind the radio. Now you can get to all of them without removing the dash. 1st remove the radio and heater controls and have and 90° angle screw driver and a lot of patience. The replacement actuators cost about $40 bucks each. Removing dash makes it easier but then it takes four times as long. With out taking out dash it can be done in about 2 hours. I done this at least 7 times in customers trucks I can do it now just under a hour.

The head unit it the easiest to replace and the most expensive about $150 bucks. Check for short circuits with a multi meter before buying parts first. I should have said that before.