Maintenance ST500 Tach-Timer
© Stack Limited
56
Use the ECU tachometer output signal in preference to the coil
negative.
No Tachometer reading
• Signal not suitable to drive a Tachometer
Signal from ignition or ECU is only 5V
Check for a more suitable connection point, such as the coil negative
signal.
• ECU or ignition system output requires a ‘pull up‘ resistor to be
fitted
Fit a 1k0 ohm (1000 ohms) resistor from the ECU/ignition to Tacho
lead, to Battery positive B+
Important: Check with the ECU/Ignition system manufacturer that
this will NOT damage their system.
Displayed speed value too high or too low by a constant %-age
amount.
• System configured with wrong number of targets per wheel
revolution
Reconfigure the system with correct values
• System configured with the wrong wheel circumference
Reconfigure the system with correct values