How do you turn on the ac manually? - Cars & Trucks

first off learn how AC works, for sure this, set of hard logic, in the system for self preservation.
and if you had used the OBD2 SCAN TOOl first after fuses checked
you'd already know this.

1. high/low, R134 pressure switch tripped saving the full destruction of the compressor. a volt meter finds this truth also.
2. the controller AC also cuts AC if engine overheats or the sensor lies.
3. the control AC cuts AC at wide open throttle.WOT
4. AC cuts AC if engine IN gross DTC errors, or in limp-home mode to protect it and the driver, so more power is on tap from engine.
5. evap core sensor , sees freeze up and icing, Ice can do damage so it cut the compressor dead(means clutch off line)
6. the controller detects ambient temps WAY to low and cuts AC.
7. The dash controller AC is failing, but manual AC? not really if it's lamp glows for AC , the main controller is BCM on most cars.
8. the dash HVAC blower must not be dead or AC stay off line

If belt is making horrible noise when you turn on the AC it is possible that the compressor is frozen and the belt is not turning the pulley.

If the AC system is properly charged you may have a controller/button problem,BCM problem or possibly a wiring issue. Very hard to pinpoint this problem without doing diagnostics

That won't burn out the compressor. It could be dead already. There are several things that will keep the light on, in the dash. High, low pressure switches, A/C .heater controller malfunction, wiring, and the compressor is bad. All these turn the light on, but all will shut down the system. Put it on a scanner and find out what's wrong.

What ac system you have automatically or manual if it manual you need to turn the button who have the color blue and red in the blue side. If it's automatically work you to verify if the blend door work.

The rear defrost is an electric switch for the defroster in the rear glass.
If you turn on the ac and do not get cold air, the first thing to check is if the compressor is running. If not, you could be low on freon or have an electrical problem in the circuit for the ac clutch.
If the compressor is running and one of the ac lines is ice cold, you could have a blend door problem under the dash.

The reason its runninig is because you have the AC turned on and when the AC is on this fan will run all the time to keep the front AC radiator cool ,if you turn the clima off you will see that it stops running .

think the dealer is half right here ,but i would need to play with it to find it have a feeling its something to with the AC where its reading the gas pressure ,but first i would make sure that the rad fan is coming on when the AC is turned on,some vehicles only turn the fan on when the temp in the AC rad get up so if its this system i would by pass this and make fan run as soon as AC is turned on because the right switch is expensive and AC has to be drained

high and low pressure swich try putting freon in it

Replace the ignition switch.