The original makers of SMITHS Instruments
Instructions for
Application Notes - For ďŹ tment to negative earth vehicles only. - Operating voltage: 11 - 17volts DC - Input signal: Petrol Engines Contact breaker ignition (coil) ECU tachometer output Diesel Engines Alternator (W terminal) - Calibration switch 8 should always be in the on position.
Calibration The tachometer is calibrated/programmed by setting a combination of seven switches located under the grommet on the back case. Remove the grommet to access the switches. Notes: - The switch setting must be completed with the power off. - Set the switches prior to installing the tachometer. The table overleaf shows the switch settings relative to the number of pulses per engine revolution. To assist with the switch setting, the table below shows the number of pulses per engine revolution versus the number of cylinders for both single spark and wasted spark ignitions.
Chronoelectric Programmable Tachometers For Petrol and Diesel Engines
Petrol Engines Only
Caution Disconnect The Negative Battery Cable Prior To Any Installation Harness connections
Independently tested and approved to 95/54/EC Designed and manufactured under ISO9001:2000 quality standard
Caerbont Automotive Instruments Ltd Abercrave, Swansea, SA9 1SH Tel: +44 (0) 1639 732200 Fax: +44 (0) 1639 732201 www.caigauge.com
Pin Wire Colour No. Connect to Green
1
Switched ignition positive 12volt supply (via 3A fuse)
Black Red/white
5 4
Chassis or battery negative Instrument illumination 12volt supply (side light feed)
White/black
6
Red/blue
7
Tacho output from ECU or contact breaker or alternator W terminal Not used
PPR - Pulses per Revolution Number of Cylinders 1 2 3 4 6 8 10 12
Single Spark Ignition 0.5 1 1.5 2 3 4 5 6
Wasted Spark Ignition 1 2 3 4 6 8 10 12
Diesel Engines Only Pulses per engine revolution (PPR) is equal to the number of alternator pole pairs multiplied by the crank to alternator pulley ratio.
PIL 048 20/05/09
PPR No.
Switch settings sw1
sw2
sw3
sw4
sw5
sw6
sw7
0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1
0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1
0 0 0 0 1 1 1 1 0 0 0 0 1 1 1 1 0 0 0 0 1 1 1 1 0 0 0 0 1 1 1 1 0 0 0 0 1 1 1 1 0 0 0 0 1 1 1 1
0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
0.5 1 1.5 2 3 4 5 6 8 8.1 8.2 8.3 8.4 8.5 8.6 8.7 8.8 8.9 9 9.1 9.2 9.3 9.4 9.5 9.6 9.7 9.8 9.9 10 10.1 10.2 10.3 10.4 10.5 10.6 10.7 10.8 10.9 11 11.1 11.2 11.3 11.4 11.5 11.6 11.7 11.8 11.9
PPR No.
Switch settings sw1
sw2
sw3
sw4
sw5
sw6
sw7
0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1
0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1
0 0 0 0 1 1 1 1 0 0 0 0 1 1 1 1 0 0 0 0 1 1 1 1 0 0 0 0 1 1 1 1 0 0 0 0 1 1 1 1 0 0 0 0 1 1 1 1
0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1
1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
12 12.1 12.2 12.3 12.4 12.5 12.6 12.7 12.8 12.9 13 13.1 13.2 13.3 13.4 13.5 13.6 13.7 13.8 13.9 14 14.25 14.5 14.75 15 15.25 15.5 15.75 16 16.25 16.5 16.75 17 17.25 17.5 17.75 18 18.25 18.5 18.75 19 19.25 19.5 19.75 20 20.25 20.5 20.75
PPR No.
Switch settings sw1
sw2
sw3
sw4
sw5
sw6
sw7
0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1
0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1
0 0 0 0 1 1 1 1 0 0 0 0 1 1 1 1 0 0 0 0 1 1 1 1 0 0 0 0 1 1 1 1
0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
21 21.25 21.5 21.75 22 22.25 22.5 22.75 23 23.25 23.5 23.75 24 24.25 24.5 24.75 25 25.25 25.5 25.75 26 26.25 26.5 26.75 27 27.25 27.5 27.75 28 28.25 28.5 28.75
Switch setting 1 signifies on Switch setting 0 signifies off Setting example: Four cylinder, single spark engine PPR is 2 From table, switch setting is: Sw1 1 On
sw2 1 on
sw3 0 off
sw4 0 off
sw5 0 off
sw6 0 off
sw7 0 off
Note: Switch number 8 should always be in the on position.