To get the twentyfive watts to transmit it takes a lot of juice. If you are coming off the ignition switch or the regular fuse panel the wiring from the batt. may not be big enough to carry the load. That causes a voltage drop and all that fancy computer stuff on the dash starts shutting down if it gets below 11 volts. Let off the button on the mike the voltage goes back up and the fishfinder , fishhawk, gps , etc all start working ok again. Run a seperate wire, fused, to the radio from the batt. and it should fix your problem.