My 2000 golf GLS started to experience the following: my remote locking and alarm system does not work, all the interior lights stays on, belt bell rings even if you you buckle your seatbelt (it turns off after a minute or so), if you turn on the headlights the on alarm starts beeping and does not turn off until you turn off the headlights, can anyone guide me to troubleshoot and fix the problem?

SOURCE: interior brake light blinking once i start driving

abs sensor

SOURCE: 2000 golf Electrical interior malfunctions.

Door switch may be sticky/ broken

Open the drivers door. With a screwdriver or equivalent trip the latch on the door 2 clicks so it is in the locked position, Just under that finger get a can of Brakecleen and hose the snot out of it. I mean really firehose it. As fast as it evaporates I still had it running out of the door drains. Be careful not to get cleaner on the plastic door panel, trust me take extra care. Open the outside door handle to release the latch, then open and shut the door for a while, like a few dozen times, to work the latch. Repeat as necessary. Follow up by shooting some PB Blaster, WD-40 or whatever light lube is handy. If this doesn’t work, give it might take a day or so to work free. If still nothing then the microswitch might actually be broken, but this usually does the trick

SOURCE: 98 volkswagon cabrio convertable gls battery & alarm trouble

I had a simular problem with my car nto starting, but the alarm didn't have issues just the headlights and the radio not turning off. I replaced the ignition switch and the problem was fixed for a while until the ignition switch malfunctioned again. The ignition switch is a cheap plastic part that connects the key to the engine, and has a tendency to break. Maybe this will help. Btw, I have a 1998 and mine is not starting well, do you know anything about #3 relays? I think I may need to replace it, so that my car will start and not putter to a stop randomly while driving. The problem only arises when the car is not yet warm. Amy ideas?

SOURCE: Mk4 Golf. Remote locking, windows and interior lights not working

Maybe fuse number 6 is blown (check lefthand side of steerning wheel where all teh fuses are located - you must open the door)

SOURCE: 2006 Jetta has interior floor

the "puddle lights" should go out about the same time as the interior lights,after removing the key from the ignition,if not try an alarm/immobiliser system reset as per the book.