What cubeice did is very similar to what I did, running it through the pigstail cord. Mine is only firmly attached to the motor housing, and able to move, if needed, from there up. The loop under the head is needed. I trashed a Transducer form a less expensive unit while going thru my learning curve. Contain without attach. I drilled a hole in the web on the motor itself to attach the cable to. A 4 inch piece of aluminum channel with grooves cut in the sides made the mount for the transom transducer that is tougher than the TM version IMHO.
Creativity is just intelligence fooling around