24 Volt 4-Wheeler electrical question.

dwhite · Nov 10, 2011

I have a 24V kids 4-wheeler. It is about 3 years old and I replaced both batteries this year. It has a fuse that keeps popping with shorter intevals. My 3yr son gets frustrated with having to wait for the fuse to cool and then reset it all the time. I'm clueless with electric stuff. Any ideas on what I should do?
Thanks

rasimmo · Nov 10, 2011

I have never torn into one of these, but I will take a stab at it. Since you can reset, it must be some sort of thermal overload. The only thing that can cause it to trip is high heat. The heat is caused by too much amp draw. That is either caused by bad wiring (current going to ground side), bad motor, or something restricting the movement making the motor work harder than it was designed to. The overload itself may be bad also. You can check the amp draw with a meter if you have one.

I have never claimed to know everything. Someone else with more experience may be able to assist more, or correct me if need be. I hope this helps.

dwhite · Nov 11, 2011

I'll try to check the current at the fuse. The wiring looks great. I suspect the motor is dying. Thanks,

jinman · Nov 11, 2011

Duane, I suspect you are exactly right about the motor drawing more current as it ages. The handlebar control is a variable resistor, I believe, and may drive a motor controller rather than directly power the motor. If the control speed is smooth and doesn't have rough or surging spots, then the motor is probably at fault. If the control is jumpy erratic, that's a sign it could be the controller. Unfortunately, these things are normally made in China and not meant to be repaired. It's a work-break-replace item.

dwhite · Nov 13, 2011

Yeah, "not meant to be repaired" is right. It's lasted 3 years and taught both my kids to drive. I just hope I can get a few more months out of it. My son will be 4 in Jan and he is almost ready to move up to his sister's 50cc gas.
Thanks,

jinman · Nov 13, 2011

From your description, it sounds like the "fuse" is really a "circuit breaker" that can be reset. If it was a replaceable fuse, I'd probably suggest going to maybe a few amps higher, but you can't do that with a breaker unless you replace the whole thing. If you do, you want to check the wires to make sure they are not getting too hot and also make sure the controller board has plenty of ventilation. You might have to do some modifications to keep the thing going. Have you jacked up or lifted the rear to see if something is binding? Any extra friction is gonna add more current to operate.

It's really a crap-shoot trying to find a problem like this. I had one of those outside fluorescent flood lights made in China go bad and quit working. The power supply for the light is in a sealed plastic case. After deciding that if it was bad, nothing would be lost, I forced the case open and found a circuit board inside with a tiny soldered-in fuse that was blown. This $40 light was fixed by just replacing a fuse, but they didn't say that anywhere and it was obvious they wanted me to just toss it and buy another one. This time, I won.

That doesn't happen often.