3TNM72 Starter Motor Assy For Excavator PC30 119125 - 77010 119125 - 77011 12V
|Part Name: Starter motor assy||Part Code: 119125 - 77011|
|Category: Spare parts||Cylinders Number: 3|
|Application: Excavator engine||Test staus: Normal|
|Type: Eddy Injection||Industrial Engine: 3TNM72|
What is a Starter Motor?
What are the symptoms of a bad starter motor: When starting a car with a fully charged battery, there is a single click or nothing happens at all. The starter motor doesn't run, even though there is a 12-Volt power at the starter control terminal.
Another symptom is when the starter motor runs, but fails to turn over the engine. Often, this might cause a loud screeching noise when starting the car. Of course, this could also be caused by damaged teeth on the ring gear of the flex plate or flywheel.
Starter solenoidStarter solenoid.A typical starter solenoid has one small connector for the starter control wire (the white connector in the photo) and two large terminals: one for the positive battery cable and the other for the thick wire that powers the starter motor itself.
The starter solenoid works as a powerful electric relay. When activated, through the control terminal, the solenoid closes the hi-current electric circuit and sends the battery power to the starter motor. At the same time, the starter solenoid pushes the starter gear forward to mesh with the ring gear of the engine flexplate or flywheel.
How the starting system works:
When you turn the ignition key to the START position, or press the START button, if the transmission is in Park or Neutral, the battery voltage goes through the starter control circuit and activates the starter solenoid. The starter solenoid powers the starter motor. At the same time, the starter solenoid pushes the starter gear forward to mesh it with the engine flywheel (flexplate in an automatic transmission). The flywheel is attached to the engine crankshaft. The starter motor spins, turning over the engine crankshaft allowing the engine to start. In cars with a push button start, the system disengages the starter as soon as the engine starts running.