Before You Start
• Read instructions completely before installing.
• ALWAYS WEAR SAFETY GLASSES.
• Install gauge when the engine is cool and ignition is off.
• Make sure all necessary tools, and parts are on hand.
• Disconnect negative (-) battery cable before installation.
General Information
• 12-volt DC negative (-) ground electrical systems
Wiring
NOTE:
Do not pull hard on the tachometer wiring.
Damage may occur.
Use 20 AWG stranded or heavier wire for
installa on. Route wires away from any moving parts and hot en-
gine components. Secure wires firmly along their route.
Note:
A s a safety precaution, the 12V power connect on
should be fused. We recommend using a 1 Amp, 3 AG fast-
acting type cartridge fuse.
Tachometer Input Signal
Connect the GREEN wire to the tachometer signal source. This
will typically be one of the following:
• ECU signal (Clean 5V square wave signal)
• Ignition coil negative terminal (May require a tach filter if signal
is noisy)
• Ignition Controller (Clean 12V square wave signal)
• HEI Tach Output (May require a tack filter if signal is noisy)
• Tachometer adapter (necessary for COP, Coil Pack, and
other modern ignition systems where one of the above signal
options is not available)
NOTE:
Signal source needs to be 2, 3 or 4 PPR to work with this
tachometer.
WIRE COLOR
GREEN
Connect to the tachomter signal source. See
Tachometer Signal Input
above.
Connect to 12V+ dash lighting
Connect to a good common ground
Connect to 12V+ ignition circuit (Tach is on/off when the Ignition is on/off)
WHITE
BLACK
RED
NOTES
Zeroing the Pointer
The pointer may have moved off zero during shipping. Perform the
following steps to zero the pointer:
1. If the pointer is below 0 turn tach power ON briefly until the
pointer moves above zero. Turn tach power OFF before the
pointer reaches 8,000 RPM. If the pointer is above zero you
can skip this step.
2. Once the pointer is above 0 turn the tach ON again and let
the pointer perform its self calibration routine. The pointer will
move to 8,000 RPM and then back to 0 RPM. The tach is now
ready to operate.
PPR Selection/Calibration
This tachometer will work on applications with signal inputs of 2,
3 and 4 pulses per revolution (PPR).
Selection of PPR is set via the switch on the back of the gauge:
• 4 = typical 4 cylinder or applications with a 2 PPR signal
• 6 = typical 6 cylinder or applications with a 3 PPR signal
• 8 = typical 8 cylinder or applications with a 4 PPR signal
No Signal or Noisy Signal?
• Verify the gauge has power and turns on. The pointer will
perform a full sweep to 8000 RPM and back to 0 RPM when
the tach is turned on.
• Verify you have a good common ground for both the
tachometer and the signal source. Ground them together to
be sure they have a common ground.
• Verify you have a good signal connection and that signal wire
is routed away from any high voltage sources that may be
introducing signal noise.
• Install a tachometer signal filter (sold separately).