Auto Trim Ii System Description; Auto Trim Ii Operation - Mercury BRAVO Service Manual

AUTO TRIM II
Auto Trim II System
Description
The Auto Trim System consists of the following major components:
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Auto Trim II Operation

The Auto Trim system is designed to allow either automatic or manual trimming of the boat
while underway - in addition to allowing sterndrive unit to be raised for trailering, beaching,
launching or shallow water operation. A 2-position switch on dashboard allows the operator
to select the mode desired.
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Auto Trim Pump - same pump that is used on the standard power trim models.
Control Module - a solid-state electronic device that senses engine rpm and regulates
the time at which the sterndrive unit trims IN and OUT when operating in the AUTO
mode. Module is protected by a 20-amp fuse.
Mode Switch - allows the operator to select either AUTO or MANUAL trim operation from
the dash.
Manual Trim Control - will only function with mode switch in the MANUAL mode and
ignition switch in the RUN position. Allows the operator to raise and lower the sterndrive
unit for trailering, beaching, launching and shallow water operation. Also, allows the
operator to manually adjust the sterndrive unit trim angle while underway in situations
where automatic trimming is not desired (rough seas, etc.).
Trim Limit Switch - Establishes the maximum trim OUT limit in both the MANUAL and
AUTO mode. Prevents sterndrive unit from moving out of the gimbal ring support
flanges, which could cause possible damage to sterndrive if it were to occur at higher
engine speeds.
SERVICE MANUAL NUMBER 28
22217
90-863160 MAY 2000