1999 VW JETTA anti-theft alarm keeps going off & car won't start

check key fob for stuck button. unhook battery in car to reset alarm. If it has a battery backup on alarm you may need to unhook it to reset the alarm.

Dude check all your fuses before you start replacing the majorly expensive relays. Be sure to disconnect battery before removing fuses. NB! disconnect earth side not live side. For more into go to the VW Polo site at http://volkswagen-polo-highline.blogspot.com

If you could disable it, they wouldn't call it anti-theft.

try turning alarm off with key under hood or bonnet

Hi there
I think it would be a good move to go to a "key-maker-person" and ask for help.
good luck
kolbrun

This is a clue, not a solution. It happens with my 1998 Jetta GT the same way, same delay. The condition comes and goes intermittently, and seems related to the trunk lock. There's a switch operated by the trunk key lock. I think that's where the problem lies. I can go for days with no problem, but sometimes after I have opened the trunk, when I lock the car the alarm goes off a minute later. Nothing will change it except opening and closing the trunk, but not every time.

anti theft has to be reset by computer or car wont start

you have to use a wiring adaptor for that year model and might have to go get one oem from dealer anti theft has been triggered and you got a serious problem.

IT COULD BE A NUMBER OF REASONS,1-the interior monitoring sensor could be faulty,2-one of the door locks could be faulty,3-the alarm horn or the alarm control unit.suggest having a dealer check for any fault codes,if none they can also check which component was the last thing to set the alarm off using their diagnostic machine...good luck

It's an ignition problem. If you keep trying to turn over it will start. It's an anti theft device they installed. The little car with the flashing key. Someone likely tampered with your ignition before for this to happen.