I am getting ready to replace my original radio/CD/cassette player in my 2001 EX with an updated aftermarket unit that has bluetooth and usb. Of course I know to disconnect the battery before getting started. I am wondering, however, is doing this going to cause an issue with the built-in alarm? Is it going to go off as soon as I get the battery reconnected because the old original unit is removed? Is it going to cause any other issues? Is the alarm still going to work if someone tries to break into the van?