1) Does the air blower work? If not, then that's your first problem.
2) Have you checked the AC fuse?
3) Carefully pull the AC relay out and swap it with the low or high beam relay, turn on the lights, check appropriately. If the lights don't work, then you need a new relay. These relays will be difficult to remove, wiggle, pull, and hold the relay box down with the other hand.
4) Check to see if the AC comes on with the temp set to cold, and the vent selector on DEF. (maybe this should be step 2) Look at the front of the pulley on the AC compressor, if it is turning then the compressor is on, if it is not turning then it's off.

OK let me know if any of those work. If the AC works on step 4, then your switch itself is bad. If you still haven't gotten it working, then we'll move on, but right now I have to give up the computer, sorry.

 

You also might try holding the switch in manually and see if it operates that way. Switches themselves are known to fail as well but I also agree on checking the fuse and the relay.

 

thanks guys\!

 

We'd appreciate an update or a resolution. I personally don't care about rep, but I do care about whether or not you were able to locate the problem, and if the advice helped, or if you found another way to check things. Feedback helps us with future diagnoses.

 

will do

 

it seems silly, but has caught me too, for the AC to come on the blower fan must be set to at least 1.

 

I'm having the same issue with my heaters... The a/c light does not show and the fans just don't work at all no matter what setting there on? Has any one worked out what this could be yet?

 

If the fans don't come on at all its the blower motor resistor should be right behind the glovebox

 

Look for fresh answer in your DUPLICATE thread here:http://www.focusfanatics.com/forum/general-technical-chat/602233-c-fans-not-working-all.html

This old thread gives suggestions for no A/C other than when the fan doesn't work, it was never updated by the OP with a resolution since posted in 2010.