Ok so I was helping a friend put in a new stereo and now the heater doesn't work. I haven't looked at it yet to see if I missed a cable but I wanted to see if there could be something else that would cause this to happen. Any thoughts?

 

Ok so over the weekend I went and looked at the car again. I found out that the person who put in the stereo before me jacked up the cable for the heater, and when i went to remove the dash it got disconnected. I reconnected it and the heater works.