Install Speedway Instruments microTach tachometer on 2004-later Harley-Davidson Motorcycle

This instructable describes how to install the Speedway Instruments microTach+TM tachometer onto any 2004 or later Harley-Davidson motorcycle. For these model bikes the digital version of the microTach+TM tachometer is used. It operates exclusively on the J1850 VPW digital data bus signal used by Harley-Davidson.

See it in action:

Installation of the Speedway Instruments microTach+ TM Tachometer requires some basic
mechanical skills, including removing decorative covers, cutting protective tubing around wires, and
using suitcase splice connectors to splice existing wiring harness. These actions may void your warranty, and if done incorrectly may cause damage to your motorcycle. Only you know your capabilities, if you do not feel capable of making modification please have a qualified motorcycle technician install it.

Variations in location, color and procedure may be required for different year and make. Please refer to the Service manual to confirm the proper color and location of wires. Please make sure you have the proper service manual and tools before starting the installation.

In these instructions we will be splicing the tachometer into the wire harness behind the speedometer. There is an alternative installation available that uses the diagnostic connector which can be downloaded from the Speedway Instruments website or another instructable is coming soon.

Step 1 : Determine a mounting position. Each motorcycle is unique and the microTach+TM tachometer is small enough to be placed in many different locations to provide an attractive appearance and vital engine status. The pictures below illustrate a number of different stups which customers have done.

Once you have determined a good mounting place, go ahead and mount it. You may consider temporary mounting using Blue painters tape. But it is probably safe to go ahead and mount it permanantly.

Step 1 Find the wires

Step 2: Remove trim around the speedometer inorder to access or determine the wire bundle which plugs into the back of the speedometer. The pictures illustrate a couple of different bikes.
1. Fatbob,
2. Sportster XLC
3. Nightster

Your bike is unique so take your time and take care to not scratch any paint.

Once you have identified the wire bundle, cut the protective tubing that surrounds the bundle to expose the individually colored wires. Make sure to expose enough wires to accomodate the 3 splice connectors in a staggered formation. Usually about 2.5" would be enough.