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Answered

Crazy cart can't run even replaced parts

I had bought a crazy cart half year ago. Few months ago, my cart stopped working so I had a check. Then I discovered that the plastic layer of the wire of the motor was melted and not in good condition so I replaced the whole motor. However when I turned on the cart after replacing the motor, the cart ran by itself without pressing the accelerate pedal. So I tested the cart again and found out that it should be something had bypassed inside the accelerate pedal. Therefore I replaced it. But after that, the cart cannot run any more, even I put the old accelerate pedal back or replace a new controller, the cart is still not working. Now it must not be the problem of the motor and the battery because I tested them by connecting them together directly, and the motor ran. Is there a way to test the controller and the accelerate pedal? If a multimeter is needed, I will get one. Also, will it be the problem of the charging port? Thanks, Jason
Best Answer

We do not test the controller's output Voltage going to the motor because due to the controller's pulse width modulation output circuit the controller's output Voltage is not pure DC power and can not be accurately read with a multimeter. Instead we test the motor by connecting it to a battery pack or DC power supply to make sure it works, and test the controller's input Voltage to determine the condition of the battery pack and parts between it and the controller.


A controller that clicks but does not operate the motor and a drop of battery pack Voltage when the throttle is pressed indicates a bad battery pack.


If the battery pack Voltage drops to 22.5 Volts or less when the throttle is pressed then the battery pack is bad and will need to be replaced. Since the Voltage is dropping near to zero that shows that the battery pack is in very poor condition.


A fully charged Crazy Cart 24 Volt battery pack should be at around 27 to 28 Volts, so if the battery pack is only at 23.7 Volts then that is also not a good sign for it.


Please let us know how it goes.

The controller can not be tested without having a test bench full of equipment specifically chosen for testing controllers. The best way to test a controller in the field is by testing all of the other parts that connect to it and using the process of elimination to determine if it is good or bad.


The first step we would take is to test the power switch for continuity. The switch should have continuity (zero resistance on a multimeter) when it is in the on position then the power switch is good.


The next step is to unplug the battery pack from the controller and test the Voltage of the battery pack harness plug. If there is Voltage at this plug then the battery pack wiring harness, fuse holder, and fuse are good.


By directly connecting the motor to the battery pack and seeing the motor spin the motor has already been tested and is good. However the Voltage of the battery pack will need to be monitored during this test to determine if the battery pack is good. The motor will run on practically any Voltage, however the controller will shut down when the battery pack Voltage goes under 22 Volts, so the Voltage of the battery pack needs to be monitored during this test to see if the battery pack Voltage is at an acceptable level under load. If the during the load test the battery pack is at 23 Volts or higher then it is good, and if it drops under 23 Volts then it is bad.


The throttle can be tested using the method below.


image


The throttle's switch should also be tested because if it does not work then the motor will not run. To test the throttle switch unplug the throttle from the controller and test the continuity of its yellow and green wires. These wires should have continuity when the throttle is pressed down, and not have continuity when the throttle is released.


Please let us know how it goes.

Thanks a lot! Gonna test it after getting a multimeter. Maybe few days later.
After buying a multimeter, I checked the battery first and it's fine as the Voltage is above 23V. Next I went to check the switch and I discovered that I had plugged the red and black wires incorrectly (the switch is fine). However(unfortunately) even if I had plugged the wires to the switch correctly, the cart still wouldn't have worked because when I was checking the throttle, there was no continuity even it was in full throttle. Probably need to fix it.
So I tried to fix the problem, and I found out that actually I had mixed up with those wires so it had no continuity. However when I plugged it into the controller, switched it on and pressed the throttle, there was no voltage coming out to the motor, but for the old throttle, there was when it was pressed. That means that actually the old throttle doesn't have problem but the new one. It was actually the old controller's problem (I tested it by switching the new controller to the old one, and there was no voltage coming out even full throttle with the old throttle). But another problem came out is that when I press into full throttle, the controller clicks and the voltage decreases near to zero. Then I release and press again, voltage rises until full throttle, controller clicks and decreases again (the highest voltage I got is 23.7V, if above, back to nearly zero ). Is that a big problem or it can be ignored? Please let me know.
Answer

We do not test the controller's output Voltage going to the motor because due to the controller's pulse width modulation output circuit the controller's output Voltage is not pure DC power and can not be accurately read with a multimeter. Instead we test the motor by connecting it to a battery pack or DC power supply to make sure it works, and test the controller's input Voltage to determine the condition of the battery pack and parts between it and the controller.


A controller that clicks but does not operate the motor and a drop of battery pack Voltage when the throttle is pressed indicates a bad battery pack.


If the battery pack Voltage drops to 22.5 Volts or less when the throttle is pressed then the battery pack is bad and will need to be replaced. Since the Voltage is dropping near to zero that shows that the battery pack is in very poor condition.


A fully charged Crazy Cart 24 Volt battery pack should be at around 27 to 28 Volts, so if the battery pack is only at 23.7 Volts then that is also not a good sign for it.


Please let us know how it goes.

Okay but actually what 23.7V means is that the highest Voltage I can get on the blue and yellow wire (controller output) by pressing the throttle. The battery is still running at its own Voltage (28.1V) to the controller. Where the Voltage dropped nearly zero when full throttle was actually on the blue and yellow wire, not the battery. However as you had mentioned before, I should not test the Voltage of the blue and yellow wire (controller output) because it is not pure DC power. I'm supposed to directly connect it to the motor to see if it runs but I forgot to tell you that I just broke the wire of the motor accidentally. So now is still the click of the controller okay?
Thanks for explaining that I was a little confused about which wires the Voltage was tested from before. The controller is supposed to click when the throttle is pressed so that is okay. Hopefully when the broken motor wire is fixed everything will work normally then.

Please let us know how it goes.
I just soldered the wires and the cart finally runs! Thank you for helping me!
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