Starting circuit
All Triumph models are equipped with an electric start system. This system consists of a starter relay, starter motor, starter switch, side stand switch, engine stop switch, clutch switch and the sprag clutch. The starter motor is connected to the starter relay and the battery by heavy duty cables in order to supply the large currents required by the motor to start the engine. When the starter button is pressed, the relay is energised, which then allows current to the starter motor. The starter motor will not operate unless the clutch lever is pulled in. Also, the starter will not operate if the side stand is down, unless the transmission is in neutral. If the starter motor does not operate, the following basic checks must be carried out before further diagnosis is performed:
- Check the engine stop switch is in the 'RUN' position.
- Check the battery terminals are clean and tight.
- Check the frame and engine ground connections are clean, tight and free from corrosion.
- Ensure the battery is fully charged and in good condition.
- Check that any fuse in the circuit is not blown and is of the correct rating.
- Using the Triumph Diagnostic Tool, check the operation of the neutral switch or gear position sensor (if fitted), side stand and clutch switches.
Note: The engine will not crank if the instruments, ABS ECM, or immobiliser/keyless ECM (if fitted)/chassis ECM (if fitted) are disconnected.
Rectify any defects as necessary.
General fault finding – starter motor and relay
Symptom | Possible cause(s) |
Starter relay does not click, starter motor does not turn | Battery discharged or defective |
Blown main or starter relay fuse | |
Defective starter relay wiring or starter switch | |
Check that the side stand, transmission and clutch lever are positioned for engine starting i.e. transmission in neutral, clutch lever pulled in and the side stand down | |
Defective alarm system - ensure any alarm fitted is working correctly | |
Starter motor turns slowly | Battery discharged or defective |
Loose, corroded or dirty battery connections | |
Loose, corroded or dirty starter motor or starter relay connections | |
Defective starter motor | |
Loose, corroded or dirty battery ground connections | |
Starter relay clicks but engine does not turn over | Battery discharged or defective |
Crankshaft does not turn due to engine defect | |
Defective starter motor | |
Starter cable open circuit | |
Defective starter relay | |
Starter motor turns but engine does not turn over | Starter motor or starter ring gear |
Diagnosis – starter circuit
Note: Prior to carrying out the diagnosis, ensure the battery voltage is 12 - 13.5 V, the immobiliser system (if fitted) is functioning correctly, the transmission is in neutral and the clutch lever is pulled fully to the handlebar.
![](https://motoinstruction.ru/img/triumph/15/121947.jpg)