Hi first post in the forums

I've been lurking the forums for some time but cannot find a specific answer to my question. Please let me know if this is not the correct sub-forum.

I bought an used 2009 Mitsubishi Lancer. When I turn on the A/C unit it emits a loud "clack" or "click" noise that can be heard inside the cabin even with windows closed. That could be probably normal when the A/C is activated for the first time, but the thing is that each time the A/C activates to keep the temperature inside the cabin, the noise can be heard and it do it a lot of times. The sound is so loud that I can be driving with windows closed and still can hear it. There is no sound if I only left the fan working. I constantly have to use the A/C because I live in Puerto Rico and it is constantly hot and humid here (typical tropical weather). With the A/C active the air flow is constantly cold and never fades out, like blowing warm or hot air unless I change the thermostat.

Is the constant "claking" sound normal? because it is very annoying

 

You have a relay that switches on the compressor and could be the culprit. Swap it with a similar (same p/n) relay (like the horn relay if the same) and then listen to determine if that fixed it.

 

Thanks Veronica,

I finally went to a mitsu dealer and they told me that there is nothing wrong with the A/C the clacking noise comes from the compressor's clutch. I'm gonna have to get use to the annoying sound.

 

mine does the same thing... btw