Does any one know where a bmw relay box is?

I have a 2002 bmw 525i. When the car is on second position I hear almost like a bird chirping from the glove back ever 10 to 15 seconds. I think it is a relay that is getting stuck but I have no idea where the relay box would be on my car.Does any one know where a bmw relay box is?Sounds like AC,heater blower to me just unplug it right side under the glove box. AND join the BMWCCA they are able to help better than I.Does any one know where a bmw relay box is?Take out the glov box znf follow the chirp!