Ok so I'm a girl, and trying to fix my heater. This plug came out from under my dash and I can't find what it plugs to.

This happened once before and the man who I bought this car from fixed it in no time. I wish I would have watched what he did.

 

Ok , 1st did the Heater stop when the plug fell out? , and by the heater not working do you mean the Fan/Blower .

The only thing i can suggest is to get a torch and climb under the dash (move the seats back) and try to have a good look for a empty socket that that plug will fit in to , i'm not even sure what side those pictures are at (LHD out here) but the blower/fan is on our LHS opposite to the driver in the passenger side sort of under/behind the Glove Box .
Good luck .

 

I'm sorry all that's going wrong for you. Unfortunately you gave us precisely 0 information to even slightly begin to guess what's going on with the system. No type, model, error codes or symptoms. Put in a service call and have them check it all out is all anyone will be able to advise based 192.168.100.1 192.168.1.1 off the post