Transducer question; dual Lowrance HDS Gen3 units

[19Roadgrader77]

I have a built in transducer Minn Kota Fortrex 80, and want to know how to unlink my units so that I’ll have sonar (only/ down imaging) off the bow for that unit? I’d prefer to NOT unlink side scan & charting with any solution.
Thanks for your help...

[mrdeath]

Might want to post this in the Lowrance forum, but to partly answer your question, the transducer built in to your Fortrex will only do sonar, not down imaging.