one for the electronc wizards
 

in the rear trunk of my 1994 w140 3.2 are a load of electrics, one of these units is a withe box with beker autoradio on it. the connector to mine is disconnected and a wire link made between terminal 13 and 5. If i remove this and reconnect it to the unit my hazard start flashing very quickly, but absolutely everything else works fine, starts, drives, alarm ok etc etc.
can anyone tell me what this unit does and why my hazards flash when its reconnected
thanks

Probably the alarm and its broken. I presume that is why it is disconnected.

would this be an expensive unit to replace

or is it repairable