Hello guys , new here . I have this weird problem of my excavator , when I turn ignition key on , the stepper motor buzzes and not moving at all , I tried buttons ( I , p ) nothing changed just short buzz every time I change the buttons , I replaced the ec motor but this didn’t change a thing , can you please help me on this one. Thanks!
The capacitor is broken
What capacitor , please !?
Generally, the starting motor has two capacitors, one starting capacitor marked CD60 and one running capacitor marked CBB60. If there is only one, it must be the starting capacitor. If the starting capacitor is damaged, the motor will hum but will not rotate. It is usually located at the cylindrical object at the motor wiring.
That’s not what I meant , I’m talking about stepper motor ( Accelerator ) in the excavator , not an AC Motor .
Check the control cable for sticking / seized between the stepping motor and the injection pump.
Thank for the reply, I removed the stepper motor from the machine , just plugging connector to make sure there is no restrictions , same thing , no movement at all just this buzzing sound. can it be the controller (EPC) faulty or something, can you provide me with some instructions on testing the voltage of the system to make sure everything is good, Thanks again
@Diesel Dave can you help me with the test procedure for the stepper motor voltages and the controller also with the angle sensor to check if everything is ok , if there is a wiring diagram and a service manual I’ll be grateful, Thanks
The only info I have is , if you backprobe terminal #2 and #3 of the EC angle sensor. The output voltage should be 4.5v at full throttle and 2.5v at slow idle speed. See screenshot below for EC angle sensor terminal locations. I have no service manual or electrical schematic for a EX60-2.
Thank you , appreciate the help . My guess is bad controller but I need to run more test to make sure it is faulty