This has been posted before but I forgot what it is called. What is the part called that I need to add when changing my stock radio with aftermarket to keep my onstar and etc working the same way? Is it called a GM modulator? I seen it talked about before with even a link to purchase it.

here is the link

Products (http://www.pac-audio.com/products/productsCatagory.asp?mmSearch=OnStar%20Interface)

depends on year of you escalade the have different options

also you may need a door shime module

He has a 2000 Lade.

He has a 2000 Lade.

for year 2000 the part # should be OS-1Bose
but they also have a note :
The OS-1Bose® will not work with OnStar® equipped vehicles that have factory radios with RDS (Class 2 headunits). Factory radio's with RDS can be indendified by locating an RDS logo on the front face of the factory radio. OS-1Bose® currently supports trucks and SUV's from 1996-2002.

by the way, nice grill on your lade. who is it made by ?

Thanks, The grill was made by X-Klusive.