RETROGAUGE™ MINI-TACH FITTING INSTRUCTIONS

The RetroGauge™ Mini-Tach is designed for use with a standard ignition coil as factory fitted to 1967 and
1968 Ford Mustangs. For aftermarket ignition systems please read the important application note at the
bottom of the page. You may also download this page as a PDF

Installation:

1. Disconnect the battery negative terminal from the vehicle to completely isolate the electrical system.
2. Remove the instrument cluster according the to the workshop manual (several internet resources are also
available to cover this procedure)
3. Unplug the instrument wiring harness from the main wiring loom and the wiper switch wiring harness from
the rear of the cluster.
4. Unscrew the speedometer cable nut and carefully withdraw the cable from the speedometer shaft.
5. Lay the cluster face down on a flat surface using a towel or similar to prevent any scratches to the
instrument bezel
6. Using a Phillips (cross head) screwdriver remove the three screws retaining the plastic blanking plate or
clock assembly. If the cluster is fitted with a clock the solitary wiring socket must be unplugged (blue with
black stripe) and securely taped back into the harness. This should NOT be used for powering the Mini-Tach.
7. Remove the Mini-Tach from the die-cut packaging and carefully fit it into the cluster ensuring the two tabs
locate in the housing flange. The Mini-Tach should now sit flush with the cluster and the three screw holes
should align.
8. Re-fit the three Phillips head screws and hand tighten.
NOTE: While the cluster is out we recommend checking and replacing all dash cluster bulbs and/or blue lighting
filters. Both items can be sourced from your favorite Mustang parts vendor.

Wiring:

1. Use minimum 18AWG (0.85mm2) automotive wiring for the connection. If possible use two different colors
for the feed and the signal inputs. Ensure the feed and signal wires are not reversed. Damage to the
electronics will occur as a result and warranty will be voided.
2. Run a wire for the Mini-Tach feed from a switched power source - preferably the ignition switch.
Ensure the wire is protected with a suitable fuse (3 amp recommended). This will be connected to the
+12VDC input terminal.
3. Run a wire for the Mini-Tach signal from the NEGATIVE side of the coil. This will be connected to the
SIGNAL input terminal. Ensure the signal wire is NOT connected to the positive side of the coil
(as was the case with the original factory tachometer).
4. The Mini-Tach has an internal grounding wire and will earth from the metal instrument cluster. If you do not
have a good ground a separate wire can be run directly from the battery negative and connected to the tab
terminal marked GROUND on the threaded stud of the Mini-Tach.
5. Re-install the cluster and connect the new feed and signal wires (and ground if necessary) to the Mini-Tach.
6. Reconnect the battery negative terminal.
7. Now start your engine and watch your new Mini-Tach fire up!

Application Note:

Most after-market electronic ignition systems are fitted with a tach drive output. In the event that this output
does not operate the Mini-Tach, an additional adaptor (amplifier or signal booster) may be required. Please check
with the manufacturer of the ignition system for the correct adaptor to suit your application. Do not connect the
signal input of the Mini-Tach directly to the coil of an electronic ignition system as damage may occur.

Warranty

RetroGauge™ Mini-Tach is 100% tested prior to being despatched. A sticker is applied to the outside of the housing at the time of checking. The Mini-Tach is calibrated to suit a 4 cycle 8 cylinder gasoline engine and is not suitable for use on any other type of engine.

We will warrant the Mini-Tach for 90 days from date of sale subject to the following: