VDO North America
Programmable Tachometer
Installation Instructions



These instructions contain information about gauges of different sizes. You must determine the size of your gauge BEFORE cutting any holes. Read these instructions thoroughly before making the installation. Do not deviate from assembly or wiring instructions. ALWAYS disconnect battery ground BEFORE making any electrical connections. If in doubt, please contact your dealer or VDO Instruments at (540)-665-2428.

Mounting dimensions vary for different gauges. Please be certain to follow the instructions for your specific gauge as described in the following paragraphs.

of the following: (1)80mm - 3 1/8" Programmable Tachometer or (1)85mm - 3 3/8" Programmable Tachometer or (1)100mm - 4" Tachometer
Two (2) Lamp Socket (Push in, wedge type)
Two (2) Light Bulb (12-volt / GE #158 or equivalent)
One (1) VDO Spin-Lok Clamp
One (1) Installation Instruction Sheet

Tools and Materials Needed for Installation:
16 Gauge stranded, insulated wire
Insulated 1/4" spade connectors
3 1/8", 3 3/8" or 4" hole saw
Drill and drill bit set
Half round file
Tape measure or ruler
Small tools: wrench or nut driver, utility knife, pliers, etc.

Tachometer Installation:
(1) Select the location where you will mount the gauge and mark a center point.
(2) Cut either a 3 1/8" or a 3 3/8" or a 4" hole, depending on the size of the tachometer you are installing. If the gauge is to snug, use a file to slightly enlarge the opening. See diagram below.

Click here to enlarge the diagram.

(3) Slip the VDO Spin-Lok Mounting Clamp over the back of the tachometer. It's direction depends on the thickness of the panel (Diagram B listed above). Tighten the clamp until the tachometer can no longer be rotated by hand. CAUTION: DO NOT OVER TIGHTEN!

Wiring the Tachometer:
(1) Run wires from the tachometer location to a positive 12 volt power terminal. (This positive power source MUST BE SWITCHED, and should be protected by a fuse); the light switch (also after the fuse box); a good ground location; and the location of the signal source (alternator, coil or other ignition signal source).
(2) Connect the wiring to the appropriate tachometer terminals as shown in diagram D below.

Click here to enlarge Diagram D.

Configuring the Tachometer:
Before your VDO Tachometer will function properly with your engine, you will need to configure it as shown in Diagram C (see below). the table at the top shows how to set the DIP switches for use with an ignition coil; the table at the bottom shows how to set the DIP switches when using the tachometer with an alternator. Note that manual fine tuning can be done using the potentiometer on the rear of the instrument. (See Diagram A). NOTE: This procedure should be done by an experienced mechanic ONLY, using a hand held reference tachometer. Fine calibration can be made between 30% and 100% using this fixed reference.

Click here to enlarge Diagram C

At this point, the installation and wiring of your new VDO Programmable Tachometer is complete. Turn on the ignition and the lights in the car and check to see that the instrument and light work properly. If they don't, re-check your wiring, referring to Diagram D.