hello all my first post, i just on a whim bought this 190e from a pal she had it from new in 1994 a 1.8 auto it has a mb alarm on with a key fob to set it and also lock the doors. thing is for some reason when setting it after a few mins the siren keeps going off then it resets then it may or may not decide to go off again. the siren and lights flash, if i lock the door with the key it doesnt go off. ive pulled the plug on the siren in the engiine bay for now any ideas help thanks