Q: Internal Wifi card turned off. Can't add to list of services

I have tried to figure out how to turn it back on. The wifi card is turned off. How do I turn it back on. I don't have backups I thought I did. I already have a terabyte specifically for mac and am planning on just transferring the important files manually and then blanking the computer installing sierra in a couple days and hope it goes well, that it turns it back on.