I've been working on my sister's car for the past few weeks while she's been away at school. She's back now, and will be taking her car back with her. I am putting the finishing touches on my work, and noticed the horn was missing the lower pitch. I found two replacements, and added both of the new horns to the car. When I was testing the horns I noticed a noise. I narrowed it down to the back of the car when I noticed the wiper was working!

I'm guessing that this must be something to do with the wires behind the airbag. I've never taken the airbag out. Do you guys think that this is where my problem lies? Has anyone else ever had this issue before?

Thanks for the feedback!