TABLE OF CONTENTS
Instrument selection & Mounting 1
Alternator Pulsed 2
Battery Ignition Pulsed 3
Pulse Generator (16 Pole), PN 71267-00 4
10&12-Pole Flywheel Alternator/Battery Ignition 5
Magnetic Sensor Pulsed 6
Pulse Generator (60 Pole), PN 71266-00 7
Dual Tachometer 8
Positive Ground & 32 Volt Applications 9
Troubleshooting & Warranty 10
INSTRUMENT SELECTION
Datcon Tachometers and Tach/Hourmeters are designed to
accommodate a wide range of gasoline and diesel engine applications;
However, each tachometer is designed for one specific signal
source. It is critical to determine the signal source before selecting a
tachometer.
Refer to the instrument's label to determine the Application code
(pulse source) of your Tachometer and proceed to the proper section
of the instructions for installation and calibration information.
All 3-3/8” Datcon tachometers are compatible with 12-volt and 24-volt
systems. The appropriate light kit (if used) must be installed.
INSTRUMENT MOUNTING
All Datcon tachometers and tach/hourmeters will fit standard SAE
panel openings of 3-3/8" or Tach Mounting Kit, Part No. 71461-00.
TIP: It is advised to connect the wiring and calibrate the unit before
final mounting. Access to the rear of the unit is required for calibration.
1
ALTERNATOR PULSED
• Connect "S" terminal to AC Tap ("R" Term) of alternator.
• Connect "I" terminal to voltage source (12/24 volts dc, neg. gnd.)
• Connect "G" terminal to a secure ground point.
• Using a master tach, determine the actual engine rpm. Adjust the
selector switch for gross calibration (close to actual engine rpm).
• Using the proper calibration tool (see instrument label), turn the
calibration "pot" until actual engine rpm is indicated.
• After the fine calibration (a few seconds after the final
adjustment), the tach will automatically reset (pointer will sweep
around) and save the calibration set point, indicating a complete
calibration.
• If the unit does not display the actual engine speed, repeat the
above calibration steps.
2
BATTERY IGNITION PULSED
NOTE: Can be used with most electronic ignition systems.
• Connect "S" terminal to negative terminal of the ignition coil.
• Connect "I" terminal to voltage source (12/24 volts dc, neg. gnd.)
• Connect "G" terminal to a suitable surface on chassis for
grounding. Avoid painted or coated surfaces.
• Set selector switch to the appropriate position.
DO NOT
adjust the calibration “pot”. These units are pre-
calibrated during assembly.
Position "4" = 4 cylinder, 4 cycle and 2 cylinder, 2 cycle
Position "6" = 6 cylinder, 4 cycle and 3 cylinder, 2 cycle
Position "8" = 8 cylinder, 4 cycle and 4 cylinder, 2 cycle
3
PULSE GENERATOR - P.N. 71267-00
• Run both sender wires to the tachometer and connect one wire to
the "S" terminal and the other wire to the “G” terminal along with
the ground wire. The sender wires have no polarity.
• Connect "I" terminal to voltage source (12/24 volts dc, neg. gnd.)
• Connect "G" terminal to a suitable surface on chassis for
grounding. Avoid painted or coated surfaces.
• Set selector switch to the appropriate position.
DO NOT
adjust the calibration “pot”. These units are pre-
calibrated during assembly.
Position "4" = .5:1 Auxiliary Drive Ratio to crank
Position "6" = 1:1 Auxiliary Drive Ratio to crank
Position "8" = 2:1 Auxiliary Drive Ratio to crank
4
10&12-POLE FLYWHEEL ALT/BATTERY IGNITION
NOTE: Can be used with most electronic ignition systems.
• Connect "S" terminal to negative terminal of the ignition coil.
• Connect "I" terminal to voltage source (12/24 volts dc, neg. gnd.)
• Connect "G" terminal to a suitable surface on chassis for
grounding. Avoid painted or coated surfaces.
• Set selector switch to the appropriate position.
DO NOT
adjust the calibration “pot”. These units are pre-
calibrated during assembly.
Position "4" = 4 cylinder, 4 cycle and 2 cylinder, 2 cycle
Position "6" = 6 cylinder, 4 cycle and 3 cylinder, 2 cycle
Position "8" = 8 cylinder, 4 cycle and 4 cylinder, 2 cycle
Position "A" = 10-pole direct-drive flywheel alternator
Position "B" = 12-pole direct-drive flywheel alternator
5
MAGNETIC SENSOR PULSED
• Connect "S" terminal to one lead of magnetic sensor. (remaining
lead to "G" terminal
• Connect "G" terminal to a secure ground point.
• Connect "I" terminal to voltage source (12/24 volts dc, neg. gnd.)
• Us
ing a master tach, determine the actual engine rpm. Adjust the
selector switch for gross calibration (close to actual engine rpm).
• Using
the proper calibration tool (see instrument label), turn the
calibration "pot" until actual engine rpm is indicated.
•
After the fine calibration (a few seconds after the final adjustment),
the tach will automatically reset (pointer will sweep around) and
save the calibration set point, indicating a complete calibration.
• If the unit does not display the actual engine speed, repeat the
above calibration steps.
•
Applicable sender part numbers:
•
71256-00 3/4-16 x 3.4" long, 71255-00 3/4-16 x 1.9" long,
71544-00 5/8-18 x 1.9" long, 71545-00 5/8-18 x 3.4" long
6