heater fan stays on after key off
 

I had the heater core replaced and the heater control dials, but when I got it back I notice that the heater fan motor runs after the key is turned off and removed, unless I manually turn the center knob off, what causes this? It worked fine before the dash was removed/reinstalled.

Now it gets even weirder. The Airbag light has started coming on, and even if I turn off the heater control switch it drains the battery totally dead.

My friend thought it could be a loose ground feeding back somehow, ideas?