AC wont work not even the ac button light will turn on Options

[mrwes09]

okay so i got another celica and its perfect for what i need it for but i notice the AC doesn't work at all... i mean
i push the button to turn on the ac but nothing happens the light doesn't turn on so i don't know if that means i have a bad relay or bad compressor
i even went n change my climate control unit (from dash) n it did the same thing so its not that ...

[VavAlephVav]

if you know the basics of how to test a relay with an ohmmeter you can check the relay. unplug the ac relay out of the black relay box under the hood and look at the little diagram on it. there are two pins that run between a symbol that should look like a little coil of wire, if you test the resistance between these two pins you should see some resistance. could be 3 ohms or 10k ohms or anything in between depending on the type of relay but there will be some reading. If it says O.L., which is open load or infinity, that is a bad coil and will not operate the switch when power is put to it.
the other pins on the relay are switch points, basically when you put power to the coil the switch changes position. and also look for other fuses to the system there may be more than one. check to see if the compressor is plugged in as well.