Bafang/8Fun motor with NO power to wheels ( help needed)

so today i went to ride my bike, which has a bafang/8fun 750W motor on it, which has worked fine until now. i made it to the corner of my street and it died. It just simply lost power to the back wheel. The throttle dosnt work, neither dose the pedal assist. The battery is fully charged, and the screen turns on like normal, but it dosnt move now.

i had a similar problem when i first got the motor, and the company fixed it, they never told me what they did or what was wrong, they just gave it back working. Is been years, so now its out of warranty. Any one got any suggestions on how to trouble shoot, and possibly fix this problem?...it got fixed once, surly i can fix it again....its my main mode of transportation, so every day of downtime sucks.

Do the cranks still turn normally? What sort of load were you putting on it? Did you hear any noises or does it make any noises now? Does your system use brake cut-offs or gear sensors? What display are you using?

its basically a really heavy bike now. the cranks work fine like a normal bike, but the motor wont power them, only my legs do.
was just my normal load going down the street to the library, turned the corner, and it stopped giving power to the wheels.
no noises of any kind, it just lost power similar to when the battery is dead, but it was full, and the screen never turned off.
it has a brake cut off..... but it also has PAS, so i think it has gear sensors too.
and the display is the old black an white one, not the newer color screen.
not sure how to trouble shoot what the problem could be, nothing i tried gave a result.

thanks, hope my answers bring some back.

Recheck all your connections, especially the motor phase wires and hall sensor connections.

Try wiggling the wires where they enter the axel. Its common for them to fatigue and break here after some time. Put some pressure on the wires there and then test again while pressure is applied.

If you have a multimeter, use it, its your friend. You want to make sure the controller is putting out voltage to the phase wires and hall sensors. If it is then chances are the issue is in the motor.

You need to tell the forum whether this is the big Bafang hubmotor in the rear wheel or if it is the Bafang mid drive motor that spins the crank. Also is it an LCD display that shows speedometer and PAS level?

Are you using brake levers wth e-switches in them that shut off the motor? Do they look OK or did they come unplugged?

lionman
yes ive checked the external connections, everything seams to be connected fine and working as far as i can tell. the only idea in i have left left is try the second brake handle that i never added on due to lack of room on my handle bars. but i have to find where i stored it first.
as for the controller, all the electronics are built into the motor itself, so to get to them i have to take it all apart, which is gonna be the last thing i try sense i m not good with circuitry. if you have more information on how to do so, that might help get me going in the right direction.

docw009
hmmm, i didnt know bafang/8fun made hub motors too, i have only seen the mid drive ones.
mine is a 750w Middrive, with pas, and the old black and white screen.

and yeah the screen and buttons work fine like normal, show all the regular numbers and whatnot.
yes, i have the one rear ebrake or whatever you wanna call it....brake with switch.
i never attached the front one due to lack of room on handle bars. The one on there seams fine, but sense the motor dosnt turn on to try to stop, i cant tell if its switch inside is faulty or not. ive been looking for the one i never attached, when i find it i will use it to see if it works and shows a fault in the other brake. But other wise, all wires are plugged in nice and tight, the magnet on the wheel is in its proper place, things turn on fine, battery is charged.... just no spin on the motor.

Hi Paradox, Bafang makes a lot of motors, almost a million a year these days, It helps when people know what system you are running. I have a fatbike with the 750W Bafang hubnotor and also a bike with the Bafang 750W mid drive.

Try unplugging the one brake lever you installed. Perhaps it is somehow turned on. That will keep the motor from spinning. Also, is there a shift sensor on your bike? That could be stuck too. It's also on a cable that runs into the motor.

Edit: On the C965 display, there is a round symbol on the LCD that comes up if the brake circuit or gear sensor are being invoked.

I apologize for the delayed response.

I have found and tried the second brake, and tried it in both brake plugins, and there was no difference.
i have tried both brakes, one brake,no brakes, mixed and matched, still, no power for both throttle, and PAS.
There is no circle, or any other indicator out of the normal. its just the usual speedometer, thermometer, PAS, Trip/odometer, battery, and light indicator ( i can post pics if you want them)
and yes, it is the C965 screen.

im not sure what to do next to find the problem.... if i can find it, i should be able to fix it.

thanks,