W203 A/C Compressor not engaging

[Yasir]

Hello, Can anybody kind enough to suggest where in my C180K W203 I can find the relay for AC compressor ? or the switch if any ?. The compressor is not kicking in so I just want to make sure its not the fuse, switch or the relay. ? I took it for re-Gas but found that the compressor was not kicking in. Thanks