Humminbird 987C SI COMBO User Manual

4

Inside the boat there is often a channel or conduit used for other wiring, this can be
used to route cables. Be sure to route the cable as far as practical from the antenna
cable of VHF radios or tachometer cables to reduce the possibility of interference. The
transducer and GPS receiver cables should not be cut, and care should be used not to
damage the cable insulation.

Basic installation tasks that you must perform include: 

• Installing the control head (choosing either gimbal or in-dash mounting)
• Installing the transducer (choosing either the transom mount or trolling motor

mounting method)

• Installing the GPS Receiver (if included)
• Installing the Speed accessory (if included)
• Testing the complete installation and locking the transducer position.

The supplied Humminbird® transducer uses a two piece kick-up mounting bracket. In
addition, if you purchased a 987c SI Combo model, you will want to install the included
GPS antenna. 

You have two choices for mounting your 900 Series™ control head:

• Gimbal mounting, where you use a surface on the boat, such as the dash, to

mount the control head so that it can be tilted up or down, or 

• In-dash mounting, where you cut a hole in the dash in order to allow the control

head to be recessed into the dash, and the control head cannot be moved after
mounting.