Longacre Autometer Tach Install Instructions - Manual

8 CYL.—NO adjustment is
necessary.
6 CYL.—Clip BROWN wire
loop only. Insulate
with electrical tape.
4 CYL.—Clip BROWN and
ORANGE wire loops.
Insulate with
electrical tape.
Calibration
IMPORTANT NOTE
This tach has an air core
meter movement. The tach
pointer may not always rest
at zero. This is normal. When
12V power is supplied,
pointer will position to the
correct rpm.
WARNING
Check with engine builder
for maximum
recommended safe shift
point before setting shift
point on tachometer. Failure
to do this could lead to
over-revving of engine,
causing serious damage to
engine and car.
CLIP NECESSARY
WIRE LOOPS. DO
NOT PUSH WIRES
INTO CASE.
Mounting
(Shift-Lite model shown)
1) 2) 3)
6) 4)
1 7 ⁄
8
”
5)
Note: Installation images shown may be different from your actual model.
WARNING
Warranty will be
void if connected
to coil on MSD
ignitions. Attach
only to tach
terminal.
Wiring
White
Red
Black
Green
Green Green
Black
12V Dash Lighting
12V Ignition
Switch (+)
Good Engine Ground
Grommet in
Firewall
OR
Early Model Ignition
Electronic Ignition
Tach
Terminal
• Shift-Lite connector must be plugged in prior to operation.
• Certain models feature a Shift-Lite plug and offer the option
to add an external Shift-Lite.
CAUTION!
As a safety precaution the Red wire of this product should be fused before connecting it to the
positive (+) side of the 12V DC battery. We recommend using a 4 Amp, 3AG fast-acting type
cartridge fuse (Littlefuse® # 312 004 or an equivalent) inline with the Red wire of our product.
FUSE
(See Caution Below)
External Shift-Lite
models only.
External Shift-Lite
models only.
IMPORTANT
WEAR
SAFETY GLASSES
2650-1077
by
®
®
NOT Valid for Race Contingency.
Model 233906 Shown Here
Cylinder Configuration
(Units without Calibration Loops)
The Cylinder Configuration mode is initiated
by pressing and holding the
top button while
turning on the 12 VDC power to the gauge.
DO NOT let go of the button until the pointer is
pointing to the desired pulses per revolution
for your engine application. For example, if
the engine ignition puts out 4 pulses per
revolution (8 cyl.), don't let go of the button
until the pointer indicates “4” (thousand).
See chart at right for details.
Every two seconds, the pointer will step to the
next major number (2 through 4). After “4”, it will
start over again at “2” and keep cycling around
until the button is released. If you miss it the first
time around, simply wait until “your number”
comes around again.
A couple of seconds after letting go of the
button, the tachometer will automatically go
into the normal operation mode and will
permanently remember this configuration
until changed again by the user.
TYPICAL ENGINE
PULSES-PER-REVOLUTION
4 CYL = 2 PULSE
6 CYL = 3 PULSE
8 CYL = 4 PULSE
Calibration Memory Tach
INSTALLATION INSTRUCTIONS
PEDESTAL ELECTRIC TACHOMETERS
1) Loosen both bolts holding the shock strap to the mounting foot.
Back both bolts out until each is only one or two turns into
the spacer.
2) Pass tach wires through shock strap assembly and slide tach
casing into shock strap assembly.
3) For external Shift-Lite models, position Shift-Lite mounting bracket
under shock strap as shown in image. Adjust Shift-Lite
(if applicable), tach, and mounting base to desired positions (see
figure 4 for recommended shock strap position), and tighten bolts
holding mounting foot to shock strap to secure the assembly.
4) Make sure rubber section of shock strap seats properly to ensure
proper fitment. Check to make sure shock strap is approximately
1
7 ⁄
8
" (1.875") between center line of strap and step of tachometer
casing for best mounting. For external Shift-Lite models, plug shift
light into tachometer connector. Plug is directional, do not force fit!
5) Recommended placement of external Shift-Lite (if applicable) is at
10 o’clock position. It is possible to place Shift-Lite in other
positions in accordance with driver preference and vehicle
mounting requirements.
6) The special design of the tachometer base allows for a variety of
mounting possibilities. Attach the base using screws provided or
use a pop rivet tool.
(Units with orange & brown loops)