I have a 1998 Z3 1.9. A couple of days ago I installed a Blaupunkt CD receiver in the car. I bought the receiver from Crutchfield who also sent me a wiring harness for my car. After I removed the factory radio (I forgot to disconnect the battery as was instructed), my remote locking/unlocking has stopped working. When I try to lock (or unlock) using the remote, the siren chirps three times as if a door is open. If I press panic on the remote, it works and then it allows me to lock and unlock the car once using the remote. But when it's locked using the remote, the alarm goes off. I tried to install the factory radio again (this time disconnecting the battery) but with the same result.
The car has the factory alarm and I read somewhere on the net that it has a hood sensor which can be easily disturbed. Everything else is working perfectly. I also checked all the fuses.
The dealer refuses to look at the problem saying that it is caused by installing a non BMW product.
Can someone help me out here.