30’ to 36’ boat owners with transom mounted transducers, I need your help

Crappy picture but you should be able to get the idea. Haven't noticed any interference from prop wash whether trolling or steaming.
 
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The B164 is old school 50khz/200khz CW sonar.The B164 is 1000W. The thru hull B164 will read bottom at speed way better than the GT56 TM.
Check the B164 wiring for the Temp(white wire)
Thanks for the advice I’ll get some help checking the wiring