A/C help!

[240WRX]

hey guys i just got my engine replace (91 240sx ka24de) and everything works fine but my A/C doesnt turn on, i checked the fuses and the relay and they are good, the a/c system is not charge at all, completly empty, but in order to charge it, i need to turn it on, the little green light on the climate control doesnt turn on either, please let me know if im missing something of if you have any ideas, thank you!!!

[0wn3r]

i'll ask the obvious...is it the control unit plugged in in the back?

[r3v_v3ng3]

check the sensor on top of the receiver/dryer

you should put the a/c system in vacuum to take all the air out then add the refrigerant

[240WRX]

yes, the control unit it is plugged, because i can turn the fan on and i can control the direction (face, feet, face and feet, windshield...) is just the A/C switch the one that doest work...

[240WRX]

can i recharge it without turning the A/C system on? i can turn the fan on and everything else, but when i press the A/C button the little green light doesnt turn on and of course the compressor doesnt kick... and before we replace the engine used to work just fine

[Doomie18]

yes you can charge it without the car being on but you would be better off taking it to a shop for them to charge it. cause u will need compressor oil and r-134 put in and its hard to do at home.