Hi I think I have a fault with the alarm on my 2000 w202,if I have the interior light set so it doesn't illuminate when door is unlocked the indicators flash 3 times when the car is locked which I assume means the alarm is on,but when I have the interior light set so it does illuminate then when I lock the car the indicators don't flash on locking the car,so I assume the alarm isn't on does that sound like a fault and if so does anybody know what could be wrong.