An idle starter solenoid can receive a large electric current from the car battery
and a small electric current from the ignition switch.
When the igenition switch is truned on, a small electric current is sent through the starter solenoid .
This cause the starter solenoid to close a pair of heavy contacts,
thus relaying a large electric current through the starter motor,
whcih in turn sets the engine in motion.
It's a solenoid starter switch.
** 12V 3P
** Working Volt : max15V
** Continuous Rating : 80A
** Pick up : < 10V
** Release : > 1.2V
** Temperature Range : -30°C ~ -80°C
**Contact Arrangement:1 Form A
**Maximum Instantaneous Current: 200A
If a starter solenoid receives insufficient power from the battery,
it will fail to start the motor, and may produce a rapid clicking sound.
The lack of power can be caused by a low battery, by corroded or loose connections in the battery cable,
or by a damaged positive (red) cable from the battery.
Any of these problems will result in some, but not enough,
power being sent to the solenoid, which means that the solenoid will only begin to push the engagement gear,
making the metallic click sound.