Replacement of factory stereo w/ newer VW model monsoon factory stereo?
 

I have 1999 VW Cabrio the stereo worked but had a few cracks so I bought a factory stereo from a 2001 VW Jetta or Golf which looks exactly like my old one but it is a "monsoon/premium". I installed the new one and it does not turn on at all. I replaced all the radio fuses and it still does not turn on. I re-installed my old stereo and itworks fine.

Does anyone know what the problem may be? Can you even use a newer model VW's facotry stereo on an older VW? The person I bought the stereo from said it worked fine before they replaced it with an aftermarket system about a year after they bought their car? Any suggestions would help. I do not know much about stereos. Thanks.