After much searching and trial and error. I have finally found the solution for my HDS 7 Touch reading water temp from the epoxied transducer in the bottom of the boat.
Change your 83/200k sonar transducer source to one that doesn't have Temp. for those freqs. put in PD-WBL
This will force unit to get the water temp from the outboard structure transducer.
Tournament Director Denton County Bass Club
Field Staff for Wicked Weights (Tungsten Done Right!)