Turned power on and when throttle is pressed you hear relay click on speed controller. Used meter to test if power going to motor. Was getting 14 volts if I'll give it 20% throttle than above that voltage drops. Battery check good. Could be a failed soped controller or something else?
over 4 years ago
The Razor Crazy Cart's controllers sends pulse width modified electricity to the motor which can not be accurately read by a multimeter, so testing the controller's motor output wires is not an accurate way to troubleshoot the problem.
However since there was electricity at the controller's motor output wires that indicates that the wiring harness, fuse, and power switch are good so you can rule them out as being the problem.
One of the most common Crazy Cart problems is a broken motor wire. To check for this problem turn the power on and press the throttle while slowly turning the steering wheel back and forth all the way from left to right. If the motor runs momentarily during this test then one of its motor wires is broken under the wire insulation and that section of the wire needs to be repaired or replaced. If the motor does not run during this test then wire the motor connector directly to a source of DC power like the cart's battery pack or a car battery charger and perform the same test. If the motor continuously runs when connected directly to a DC power source and the steering wheel is turned all the way from left to right then it and its wires are good and the problem is elsewhere.
The next most common problem is a battery pack that drops too much Voltage under load. When the battery pack Voltage drops under 23 Volts the controller will not run the motor. To load test the battery pack, monitor its Voltage when the power switch is on and the throttle is fully pressed. It will not drop under 23 Volts during this test if the battery pack is good. If it drops under 23 Volts then it needs to be replaced. This load test will not work if a motor wire is broken, or another part has failed, so it is best to perform this test after testing the motor wires.
The batteries can also be load tested with a carbon pile battery load tester, or at a local battery store, for a more accurate load test without interference from possible faulty parts on the cart.
The problem could also be the controller, however there is no way to test the controller without having a test bench full of equipment specifically designed for testing controllers, so testing the other parts that are connected to the controller is the best way to diagnose the problem outside of a repair shop.
Hopefully this will help you to successfully diagnose the problem. Please let us know how if you have any questions, and how it goes.