INSTALLATION INSTRUCTIONS
TACH ADAPTER
®
2650-561X-10 Rev.C
CAUTION!!!
The Tach Adapter cannot be used with a Capacitive Discharge Ignition (such as an
MSD Ignition Control). The voltage on the coil positive must be below 18 volts.
Installation
Parts Included: 1 - Tach Adapter 9117
1 - Butt Connector
3 - Mounting Screws
2 - Bullet Connectors
The Auto Meter Tach Adapter wires in line on the positive 12 volt supply wire. It senses current on the coil positive wire and converts it to a 12
volt signal output. To install the Tach Adapter, the coil positive wire must be identified for your application. Once the wire has been located it is
recommended to check for 12 volts using a volt meter. Connect the meter and turn the ignition On. In some cases, the engine must be cranked over
in order to see 12 volts.
The Tach Adapter is designed to be mounted under the hood. The circuits are potted in polyurethane for water resistance and vibration protection.
Position the Tach Adapter away from excessive heat sources and mark the locations of the three mounting holes. Use a
5
⁄
32
” bit to drill holes and
secure the unit with the supplied screws.
Route the wires away from direct heat sources, moving components, and sharp edges. Use the supplied bullet terminals on the 12 volt coil wire.
(These terminals are supplied so the wiring can be returned to stock if ever desired.) The butt splice crimp connector is used for the Gray tach output
lead and the tach trigger wire.
WIRING
RED
- Input, connects to the ignition 12 volt supply coming from the ignition switch.
RED/GREEN
- Output, connects to the coil positive wire.
BLACK
- Connects to engine ground.
GRAY
- Tach output signal wire. Connects to the green Tach trigger wire or other RPM operated component.
Connecting to Coil Per Cylinder
(Other Ford cars & Trucks may be the same as below, but with different 42 pin connector location)
TYPICAL ‘99 - 04 MUSTANG
Locate the large, square 42 pin wire harness connector in the corner of the engine bay where the passenger fender meets the firewall. Pop the
plastic cover off the top of this connector to expose where the wires enter the connector and to expose the wire pin numbers. Locate pin number
34 which will be in the corner of this connector. Depending on the specific year and trim of Mustang, the wire color can be Red, Red with a Green
stripe, or a White wire with a Blue stripe. Cut this wire in half so that you now have two cut halves. Hook the Red wire of the adaptor to the cut half
coming from the connector. Hook the Red/Green of the adapter to the other cut half. Ground the Black wire of the adaptor. The Gray wire of the
adapter will now provide you with a good tachometer signal.
42 Pin Harness
Connector
ENGINE COMPARTMENT VIEW
CLOSE-UP VIEW OF 42 PIN CONNECTOR.
Pin #34 may be Red,
Red/Green or White/Blue
depending on year
(Position of Numbers May Vary)
