How to Wire Gauges for Two Outboards

Wiring the gauges for multiple engines means connecting the instrument feed wires to the gauges. The instrument feed wires provide the data that the gauges interpret and display. Each motor has its own instrument feed wire that you will connect to the individual gauge. For night boating, the instruments must be lighted. Fortunately, you can connect the instruments in a chain, one to another. Each gauge must also have its own connection to the boat's ground, to complete the circuit that powers the gauge.

Things You'll Need

  • Screwdriver
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Instructions

    • 1

      Loosen the screw of the "S" terminal on the back of the port -- left -- gauge using a screwdriver. Push the spade terminal of the instrument feed wire from the port engine under the screw. Tighten the screw.

    • 2

      Repeat Step 1, connecting the instrument feed wire from the starboard -- right -- engine to the starboard gauge. Note that tachometer feed wires are gray, while all others are purple or red.

    • 3

      Loosen the screw of the "L" terminal on the rear of the gauge to the right of the gauge you are installing. Slip the spade terminal on the new gauge's dark blue wire under the screw of the "L" terminal on the gauge to its right. Tighten the screw.

    • 4

      Loosen a screw on the common ground bus under the dash. Slide the spade terminal of the ground wire -- either black or green -- of the new gauge under the common ground screw. Tighten the screw.

    • 5

      Repeat the same process for the tachometer, the ammeter and the temperature gauges.