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3/6/2008   2003 Harley Davidson Fat Boy Pro-Cycle 19466 Tach/Speedo Combo Installation Guide

Here's what came stock on our bike, it had served its purpose well, but it's time to say goodbye...

Our tech department has been hard at work to get you the information you need to monitor your bike's vitals. This time we're taking an in depth look at how to hook up one of our new 19466 Tach/Speedo Combos on an 03 Harley Davidson Fat Boy.

Though this install was performed on the 03 Harley Davidson model, much of the information provided below will prove helpful to owners of the 98-02 models as well.

Let's get started!

Important! First things first, disconnect the battery before moving on with the rest of the install!


We laid a soft towel on the tank to protect the paint and simply lifted up on the console assembly and laid it over to rest on the tank. See Image Below.

Removal of the original speedometer:

Remove the large acorn nut on the console, located just below the original speedometer.


This is the Pro-Cycle 19466 tach speedo combo that will be replacing that stock speedo.

Unplug both wire harness connectors (1 to the speedometer, the other for the ignition switch and indicators). This way you can remove the console completely from the bike and work with it on a suitable work bench if desired.

There is a plastic retaining ring that holds the original speedometer in place with 3 spots on it that clip onto the speedometer.

Note: This is part of the process is easier with an assistant.

Use your fingers (against the 2 curved portions of the retainer) to push the retainer away from the speedometer.


Slide the speedometer out carefully as it becomes freed from the retainer.

There will be a rubber seal around the original speedometer where it goes through the hole in the console.

Retain this and install into the console gauge opening if it came out during the removal of the original speedometer. You will not re-use the original speedometer or retaining ring.

Mounting the Tach/Speedo Combo:

Insert the Pro-Cycle 19466 combo into the original opening in the console, through the rubber seal.


From the back side, install the new, supplied metal retaining bracket with the aluminum thumb nuts provided. It will only fit one way.

Wiring power, ground, and tach signal to the tach/speedo combo:

Using the chart at the beginning of the supplied instructions that come with the gauge, you may begin your wiring. There are several wire connections that need to be made for the proper operation of this instrument. We recommend that you cut one wire from the factory speedometer wire harness connector at a time for simplicity's sake.

We started with power (orange/white), then ground (black), then tachometer (pink) and moved on from there. When we cut each wire, we used the supplied female spade terminal (also known as “quick disconnect” terminals), and tightly crimped the terminals with a good quality pair of wire crimpers.

As we cut and terminated each wire, we immediately plugged it into the appropriate terminal on the back of the new gauge.


Wiring the trip/reset/calibration button:

We used the factory button on the side of the console. There are two wires on that button. On our bike, both wires were gray. One will go to the “SW” terminal, and the other will go the “SW RTN” terminal on the back of the tach/speedo combo. It does not matter which button wire goes to which terminal.

If you do not have an existing trip reset button, you may use any momentary, 2-terminal button of your choice.



Wiring the speed sensor:

If you are using an earlier 12v speed sensor, or an after market that accepts a 12v input, there will then be no need for the regulator and you may share power and ground directly from the speedometer. “Splitters” are supplied with the tach/speedo combo to allow two wires to be plugged onto one terminal at the back of the instrument head for this reason.



In our application, the speed sensor originally used a 5v input, supplied from the original speedometer head. Please call Auto Meter, or check with Harley if you are unsure of what your sensor uses for an input. Supplying 12v to a 5v sensor will result in failure of the sensor.

We used a Radio Shack voltage regulator to step the power down to a fixed 5v signal. Using the same power and ground as the speedometer head uses to the regulator, you will then run your power to the speed sensor from the output of the regulator. The Radio Shack number is 276-1770.


Final Assembly:

Neatly bundle, tape, and/or zip tie any wiring in such a manner that it will not rub through any components. Re-installing the console will also require that you carefully locate and route the harnesses in order for the console to sit all the way down on the tank. Try to route the harnesses around or under the gauge mounting bracket, rather than over it (as they appear in this picture). Re-install the acorn nut.

NOTE: It is a good idea to test the function of the new unit prior to final assembly. Reconnect the battery and make sure that all connections at the back of the new gauge are tight fitting.


The finished product!

The last thing needed to finalize the install is to take the bike out on the required 2 mile calibration distance and follow the calibration procedure as outlined in the instructions.



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