Honda anti theft code on radio?

i just financed a 96 honda accord ex from a little delership and i took it home and looked it over including under the hood.....while i was doin so i noticed the battery terminal was covered in thick corrosion i romoved the terminal and cleaned it off and put it back on, with out thinking about the anti theft device on the radio.....now when i turn the radio on it says code and wont let me use it..... i know im supposed to call a honda dealership to get the code but i heard tht cost about 90 dollars which is stupid......im eventually gonna go with a aftermarket cd player but for now i would like to use the stock until then.....does anyone know it the code is located on the back of the deck or if there is a free way to get it without having to call a dealship and deal with there scams? also the top idler pulley wiggles when the car is running but when the car is off i tried wiggleing it with my hand and both the wheel and the nut are tight and wont budge? why would it wiggle while the car is running and is this normal?