What was the cost for the head unit?
It was under $300 from Trollingmotorparts.com
I thought the Ultrex came out when they had improved spotlock accuracy. Have you tried adjusting the settings in the TM remote? Sometimes changing the boat size helps it from over correcting so much
I tried everything. The controller simply wasn't working right. I did make adjustments on the boat size as when I first used it the sucker tried to throw me out of the boat left and right when it would act squirrely. Replacement made the difference. And of course right after the foot pedal steering sensor went out. Replaced that too and good to go.