Trim System OE#818186A6 OE# 818186A6 3 wire 3 ram system for Mercury/Mariner power trim and tilt complete system. 1984-1995 Replaces design I side fill and design II aft fill Fits Mercury O/B 35 – 225 HP 1985- 1995, 3-ram power trim/tilt system. Original Mercury system was 3-wire and new replacement TT2000 system is 2-wire and is supplied with a conversion wire harness. Replaces Mercury #’s 99659A21, 99659A22, 99186, 99186T