I just helped a friend install a gamin 741xs in his boat so that he could delete the old standard gauges. His engine is a merc 525. During this process he added an ITS transom and new merc k-planes all with digital trim senders. So far all the engine data and drive trim is showing correctly on the screen but we have not been able to see the trim indicators for the tabs. Any help would be greatly appreciated in solving this one little problem

Could a moderator move this to the electronics forum

Your friend needs a Mercury Trim Tab Interface Kit.