Have you checked the wire for a shorted circuit with a multi-meter (or an ohm-meter or something like that).
Just check whether the pin in the connector (probably with black/yellow/green or blue/black wire) is connected to ground.

greetingz,

__________________
1990 300SL-24
1993 C250D with a minor 600+k kilometer
www.MBenzNL.com(the Netherlands)