2 cent tip. 1. First, carefully unplug everything from the DMD Units and remove the DMD Units and the receiver from the KT hull. 2. Charge your tank battery and make sure the transmitter has good batterie(s). 3. Again, with DMD Units out of and away from the KT hull, plug in the speaker and the receiver per the directions. 4. Reprogram the units per the instructions and you should now be OK. 5. If your on old AM, make sure there is no interference going on around the DMD units.