Abstract: A method of detonating one or more pyrotechnic devices located within a motor vehicle comprises: locating the detonation control unit of the vehicle; removing the vehicle wiring loom connector from the detonation control unit; connecting the said connector to a first connector (4) provided at one end of a detonation control cable, the detonation control cable including, in addition to a first connector (4) for mating with the wiring loom connector, a length of cable (2) and a second connector (3) for connection to a detonation device, and incorporating means for rendering unusable the detonation control cable after a single use; connecting the second connector (3) of the detonation control cable to an external detonation device; and operating the external detonation device to detonate all the pyrotechnic devices within the vehicle via the wiring loom of the vehicle and, at the same time, to render the detonation control cable incapable of further use.