Alarm system won't disarm HELP!!
 

We just purchased a 1987 300TD Turbo and it has the factory alarm system. The 2 times we test drove this car, we had no problem, but shortly after getting it home, the first time I locked it, then unlocked it, opened the door, the alarm went off . I used the key with the red dot on it which is supposed to disarm the system when you unlock the doors. What I have done for now is disconnect the alarm horn to spare the neighbors, but the lights flash for the duration of the alarm. I have locked and unlock the doors to reset the sys., but no luck. Somewhere I heard that if the car battery is old, this alarm problem can happen. The battery in this car is 4 years old, but reads a solid 12 volts. ANY ideas would be appreciated.

Hi,

To disconnect the alarm, you have to find the box under the passenger footwell. Remove carpeting and look for a box with two connectors 12 pins per connector I believe. It will be right under where the front passenger's feet usually rest.

Undo both connectors.

Search the archives about alarm faults. Usually the locking mechanism on the driver's side wears out. You can try switching the passenger-side mechanism with the driver's side.

Good luck,

Thanks, I'll look for that box. I am more familar with the W123 and W116 chassises (sp). Can the whole door handle form the driver's side be swapped with the passenger's? Since I just got this car, I haven't had a chance to take it apart to fix the "little" things that need attention. I imagine there are some wires going to the lock mechanism in the driver's door.

Hi,

No, I believe just the locking mechanism can be switched.

Regards,

I found the box and took off the large connector and the flashing lights stopped. Nothing else seemed to be affected, so all is good for now. Thanks for the tip.