If you are using the HB TS3 switch ....It works kinda like a train track switch ...
In position 1 - the sonar data flows directly thru cable 1 ...(no 12v power needed in this position) ...
In position 2 - the 12v power engages the relay in the TS3 to "push" the switch to connect cable 2...
If the HB TS3 switch is left in this position 2 - 12v power is continuously sending juice to the relay ...
I put a 12v toggle switch in front of my HB TS3 switch so that I could kill the power completely to the HB TS3 switch ...
This way I don't have to remember which side of the HB TS3 switch is powered and which side is not ...
Rickie