Mercury Smartcaft MercMonitor Installation

By Trashy

I. Acknowledgements
II. Introduction
III. Parts Needed
IV. Tools Needed
V. Supplies Needed
VI. General Notes
1. Step One - Remove Any Old Instruments and Wiring Not Needed
2. Step Two - Routing Harnesses
3. Step Three - Installing the New Gauge
4. Step Four - Making the Connections
5. Step Five - Configuration
6. Step Six - Testing

Acknowledgements

First of all, I need to thank the following people.

Don Weed, owner of European Marine in South Carolina, and moderator of the 3 Liter High Performance forum on Bass Boat Central. He was very kind enough to get me the parts that I needed for my installation, and customer service was TOP NOTCH!

bigbasser54, member of Bass Boat Central that took the time to take some of the photos used for this page, and gave instructions for taking apart the Smartcraft connector.

Introduction

I'm going to describe how to install a MercMonitor version 4 and interface it with a Lowrance LMS-332C.

The first thing you need to do is order the right parts for your particular application. Consult your Mercury Dealer for anything different for your application.

DISCLAIMER! This is what I did to get my equipment working. Follow these instructions at your own risk!

Parts Needed

MercMonitor - part number 87933K02
Smartcraft Harness - part number 879982T20
Gender Adapter Harnes - part number 892452A01
Fuel/Oil Harness - part number 859743T03

Once again, consult your Mercury Dealer for what you will need for your particular application.

Tools Needed

Basic set of hand tools
Wire Strippers
Heat Gun
Crimpers
Method to "Fish" wires through the boat and/or rigging tubes. I use an old fiberglass fishing pole with the eyelets cut off and some string. I also have a fish tape that can be purchased at most any hardware store.

Other Supplies Needed

Length of wire, preferably black, marine grade and a minumum of 20 gauge.
Wire Splices - both red and blue I like to use environmental splices that come with heat shrink to cover the connection.
Heat Shrink Tubing - I prefer to use the type that has adhesive.
Cable Ties
Ring Terminals
Electrical Tape
Masking Tape
Sharpie
Notepad and pen/pencil
Digital Camera (optional)

General Notes

I highly recommend taking notes as much as possible, and even using a digital camera to take pictures prior to disconnecting anything. I also use a piece of masking tape and a sharpie to mark wires temporarily.

Regarding connecting to a GPS. In my case I connected to a Lowrance. The wire colors apply ONLY to the unit that I have. Consult your owners manual for information regarding your particular GPS. I assume that pretty much any GPS capable of using NMEA 0183 can be used. You basically need to connect the Transmit Wire from your hardware and the ground to make it work.

Step I - Remove any old instruments and wiring not needed.

The first thing to do is trim the motor down, then DISCONNECT the battery.

In this step, I chose to remove my speedometer since it was never functional to begin with. Removal is as simple as loosening the two nuts holding the back plate onto the gauge and removing the gauge itself. The lighting circuit was hooked up on this gauge is no longer needed, so the lighting wire was capped off and stowed, and the ground wire was used for part of the installation.

Step II - Routing the new harnesses through the boat and the rigging tube going to the motor

Routing the new harness through the boat can be tricky, and this is the hardest part.

It is much easier to take the connector off of the harness, and re-install it after pulling the cables to their final destination. Here is the procedure that I followed, thanks to bigbasser54 of BassBoatCentral.

Carefully run the rod from the back of the boat towards the front. Using some elecrical tape, tape the cable end marked "to engine" to the tip of the rod, and pull it to the back of the boat. <insert picture>

Running the cable through the rigging tube to the motor is another difficult and time consuming task. Use the same method to pull the Smartcraft cable and the Fuel/Oil harness through the rigging tube from the bilge compartment to the motor. <insert picture>

Step III - Installing the new Gauge

Installing the gauge is simple. In this case I simply put the gauge into the bezel, then ran it thought the dash. The lock ring goes on the back side. <insert picture>

If you are doing a new install, follow the directions here for cutting a new hole.

Step IV - Making The Connections

Installing With Interface To GPS

If you are not going to interface with your GPS system, you can skip down to "Installing Without Interface to GPS".

First take the cable from the instrument that has a few single wires coming out of it. It has a large connector that plugs into the back of the gauge, a smaller connector that will plug into the main harness, and an even smaller connector to plug into optional accessories. It should look something like this.

We will be connecting a few wires that are hanging off of it, and leaving some of them stowed. The wires that we are going to connect are white/blue, blue/white and black.

NOTE: If desired, the warning horn circuit can be connected, but I didn't do so with my setup. Typically, the purple wire will go to a circuit that has power with the key on, and the tan/black wire would connect to one side of your warning horn. For my installation, I left these wires capped off and stowed.

Locate the power cable from your Lowrance GPS. It should have 3 wire assemblies coming off of it. One of the wire assemblies will have 4 wires coming out of it, and is probably not connected to anything. There should be a blue, yellow, orange and bare wire coming out of the assembly. It should look similar to this.

We only use two of the wires (the yellow and the bare wire) so the other two wires are capped off with some heat shrink.

Take the bare wire and the blue/white wire from the MercMonitor cable and put them in one end of a splice. On the other end splice a new piece of wire that will connectto the cranking battery ground. In this case, I used a piece of black marine grade 18 gauge wire.

Next, splice the yellow wire from the Lowrance to the white/blue stripe wire from the MercMonitor. Be sure to cover the connections with heat shrink.

Here is a picture of the wires after being splice and prior to the heat shrink installed.

A picture of the splice heat shrink applied.

And finally, the whole connection covered with heat shrink.

Next take the black wire from the Mercmonitor harness, along with the new wire spliced to the blue/white and bare wire from the Lowrance, and connect them to battery negative. In my case, I used some ring terminals with heat shrink and connected them to a couple of spare ground terminals on my fuse block.

Installing Without Interface to GPS

On the motor end, connect the blue Smartcraft harness onto the free port on the engine. NOTE! This port will probably have a yellow cap on it with a terminating resistor.

At the other end of the blue cable, connect the "gender bender" between the blue cable where it is marked "gauge" and the MercMonitor cable where it is marked "junction box".

Connect the black cable from the MercMonitor harness to battery negative. In my case, I connected it to a spare terminal on my fuse block for engine ground. NOTE! If you followed the instructions for Installing With Interface to GPS, this step has already been completed.

Finally, connect the MercMonitor cable to the instrument. The connector is pretty obvious, it is labeled "gauge" and is the largest connector on the harness.

Step V - Configuration

The next thing that needs to be done is to set up the Lowrance unit to communicate with the MercMonitor. Power it up, and make sure that you have the boat outside where the GPS can lock onto the satellites.

Hit the menu button twice, and scroll down to System Setup, then select Communications Port.

Note: Click on the following pictures to see a larger version.

Make sure that "NMEA 0183 Output: is checked, and the baud rate is set to 4800.

Next, select the "Configure NMEA 0183" button.

Make sure everything in the top portion under GPS is checked, and everything in the Sonar section is UN-CHECKED.

Next, turn the key on and power up the MercMonitor. It should display a screen telling you to press the "Mode" button to start the automatic detection of your engine. Go ahead and press it and wait until it's finished (this took mine roughly 10 seconds if I remember right).

Hit the mode button, and use the "-" button to scroll down to the Settings Menu. Hit the "mode" button again and scroll down to "Ext. Sensors" and use the "mode" button to enter the sub-menu.

Press the "-" key to scroll down the the GPS Enabled option and hit "Mode" to change it to display "yes".

Press the "-" or "+" key to highlight the Speed option and hit "Mode" to edit it. Make sure that "Use Paddle" and "Use Pitot" are set to "No" and "Use GPS Speed is set to "Yes". After setting these options be sure to choose "Save" when prompted and scroll down to "Exit" as needed.

Again under the "Settings" menu choose "Clock" . Under there, you can set the clock to use a 24h format or a 12h format. I chose 12h but that's a personal choice. Go down and highlight GPS Update and select it to "Yes". Next select GPS UTC and set it for your time zone. Eastern Time is -4, Central Time is -5, etc. You may need to play with this setting to get the time correct.

Once done save and/or exit out of all the menus, and go back to the "Settings" menu and select "Full Screens". Here you can choose what you want displayed and you can customize your Tri-Data. Consult the manual for further information on these settings.