Mercury - Side Mount Control Harness, No Trim, 20 ft 84-8M0143200. The Mercury Side Mount Control Harness (No Trim) is designed for mechanical side-mount control systems on engines that do not use power trim. This harness provides a clean electrical connection between the control box and the engine while keeping the wiring setup simple and uncluttered. Its 20-foot length supports easier routing on wider hulls and center-console layouts, making it well-suited for new installations or replacing ol