Hello & Welcome to Just Answer,
Sorry to hear of any trouble you may be having connecting this device.
The answer is NO - do NOT connect the tx & rx wires to the battery at all - they are used for connecting to NMEA 0183 devices - to be able to communicate with them.
Let me send you a link to the installation instructions for this series of devices - which has DETAILED information about how to connect the wiring harness & wires within.
Click here --> http://static.garmin.com/pumac/echoMAP_4x-5x_Install_EN.pdf
NOTE: If you don't have any other devices to connect to, I would just tape the ends off - with electrical tape.
Please let me know if you have any more questions.
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