Okay, I believe your right about it being the impact sensor for the airbags. It is located on the top side of the fenderwell/wheelwell next to the front clip. I just got the truck fired back up and the airbag light is on.

 

you could plug it back in and smack it with a hammer, if the airbag goes off then it is that sensor

 

Yeah, I'm afraid to hook it back up. I could probably patch the connector back together, but there are 2 wires, and I don't know which goes where. I guess I've got a 50% chance of the air bag going ka-boom!

 

Don't F with it unless you are sure you can get the wires right, and disconnect the battery while you screw with it or replace it. I would just leave it alone for now until you get a replacement. You can drive it with the lite on, but...........

 

Look at the other side and that will tell you how it should be hooked up.