INSTRUMENT RELY PACK TRANSMITTER OPERATION -* 1.0pen the battery door by sliding towards the arrow. 2.insert a 9V battery into the battery holder according to indication marked on the battery housing. 3. S1ide the battery door back on until it locks. 4.Push the power switch to the "ON" position. The LED will illuminate RED. If the LED indicator does not go on at all, it indicates that the battery is dither dead or not properly inserted. Check the battery positioning and try again.