My 2003 mitsubishi eclipse spyder anti-theft system won`t shut down. I tried to disarm it according to the manual but nothing happens. I took the horn fuse out and it just changed the tone of the horn and kept on honking and the lights kept flashing. It continues for about 3 minutes then stops, but as soon as I open the door it starts up again. Any suggestions?

Disconnect battery and join the cables together for a while if that doesnt work then disconnect battery and call the breakdown truck to take it to the dealer who has the right diagnostic software to sort the problem out for you .This is not a home repair type job

I had the same problem and you can isolate the relay by feeling it as the alarm is engaged, it makes a clicking noise but you can also feel it when it switches. Pulling the relay will pacify the noise as a temporary fix. The ultimate solution for me was replacing the alternator. It turned out that the alarm malfunctions for me were just precursors to the bigger issue cause by the change in voltage input due to lack of charge. If you have a battery light that comes on while driving be aware that you may have a bigger issue. Let me know if I've helped at all.