1998 7 series , my lights blink when I use the key , but no siren , no beep beep, car locks but no siren sound replaced siren still no sound/ chirp
You might want to check the alarm hood switch it might be misaligned or its gone bad. Your battery might have a low voltage, run a voltage check through the OBC.
Check the cable if it is bringing you electricity to the siren ? Check fuse ? Check switch ?