It depends on where the tamper fault is. I'm assuming you have also had to relocate all the wiring to the panel so the two main possible causes are a loose panel lid or a wiring fault in the detectors tamper circuit or a bell box tamper fault.
CHECK THE PANEL LID FIRST!!
You will have to connect a multi meter ( set to measure continuity) between the A/T terminals on the right hand side of the panel circuit board & you need to have confirmation of a closed circuit.
To check the bell box tamper you have to connect a multi meter (set to 12 volt dc) with the red lead to terminal +12v & the black lead to terminal TR on the bottom of the circuit board. You need to have a reading of at least 12 volts or more (usually 13volts).
John, Alarms Direct, April 2009