Taylor pickup quetion

[raider4life]

I have a 812-C Taylor acoustic. I got it from someone I work with. It has an input on the bottom strap nut, but when I plug it into an amp I get nothing. I've looked inside and I see a black and red wire going to a square-ish box near the top of the body. I would have figured this for a battery housing but on the outside there is no equalizers, volume knob, etc... Please someone give me an idea of what it is?? My only thought is maybe it was getting a mic installed but it wasn't finished. Thanks