Looking at 1999 D1 that has a Alarm/Security issue. It goes like this- put the key in the door to unlock (central locking does not work/other doors do not unlock), open drivers door (no dome light), notice rapid red LED light on dash is flashing, put the key in ignition and tried to start it and horn goes off, turn the key off and it stops, then the horn sounds like its trying to sound off but instead makes a clicking/chirping noise (like low voltage). Tried checking battery and even hooked up my truck to it with jumper cables and still no change.
Tried opening passenger door with key and starting it but still the same.
Is this anything anyone has experienced??