Hi .I have a problem with one of my k plain trim tabs . seams to creep up on its own . send it down 5 mins later creeps back up . Can you help
Thanks Ricky

I assume this is while running the boat?? Most likely have a bad valve/seal in the pump

Hi while running.
is there check valve in pump
thanks for that Ricky

Do you have mechanical or digital indicators? Also does your boat coincide with what indicator is showing? I had a 28 saber with a single years ago and it would out of the blue take a set at cruising speeds to wot. Manual indicators never fluctuated. I figured it was air in the line. Either tab would budge up or down on trailer. Even with force. Sold boat shortly there after but told buyer.

Almost seems like your getting voltage to the switch or a faulty switch.

Sound like your problem?

Hi . All mechanical cable old style presto pump op . I think pos one way valve in pump Thanks for help