Without knowing what system it is difficult to give you an accurate answer. Instead I will advise how a window contact works: A window contact is no more than a reed-switch in a vacuum sealed tube and a magnet, the magnet attaches to the window, the reed attaches to the frame. The magnet has to be within circa 5mm and aligned with the reed. To check the contact you need a DMM (Digital MultiMeter) set on a continuity setting (Buzzer). To test the window contact - connect the DMM accross the reed-switch - when the window is closed (magnet next to reed-switch) the DMM will buzz, else it will not. If the DMM fails to buzz you have a dead contact. Contacts are cheap, circa £1.50. It is not uncommon for surface mounted contacts to corrode and fail due to water ingress. Please note that you may also need to check the cable between the contact and alarm system as this may have become damaged.
PR Shields
May 2009
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