Troubleshooting a controller and hub motor

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Last seen: 11 years 7 months ago
Joined: Tuesday, July 5, 2011 - 07:52
Points: 3
Troubleshooting a controller and hub motor

Morning! New to the fact I'm new to electric bikes. I own a small bike shop and a customer brought in his X-treme XB-502 (as best I can tell that's the model it has 4 12v12aH batteries) and the fuse blows. I started working on it by inserting a new fuse (key OFF) and it violently blew the fuse. Upon a great bit of troubleshooting and wire chasing, etc. when I unplug the yellow wire from the controller to the hub it won't blow the fuse. As soon as I attempt to plug in the yellow wire, it gives a nice light show when blowing the fuse.

I hit the yellow wire with my VOM and I have 48volts (and apparently a fair bit of amps :). So, my questions are these:

1) Should I have 48v on the yellow wire out of the controller with the key off?

2) Anyone have a good set of wiring diagrams and troubleshooting tables?

Thanks so much in advance, looking forward to working more and more on these bikes!


Last seen: 11 years 7 months ago
Joined: Friday, July 8, 2011 - 23:25
Points: 13
Re: Troubleshooting a controller and hub motor

Sounds like what my xb 500 is doing and the rear wheel does not spin feely anymore either, im thinking its the hub motor...when i put a new fuse in with the key off it blew violently...

Last seen: 1 month 6 hours ago
Joined: Saturday, July 7, 2007 - 23:55
Points: 1686
Re: Troubleshooting a controller and hub motor

A failed hub motor won't cause the fuse to blow when everything is off.
Only a failed motor controller will do that (failed FETS on two phases)

when the hub motor is not wired, does it now turn freely?
if yes, the motor is fine.
If not, the motor has *also* failed. make good BLDC motor controllers


Daily Ride:
2007 Vectrix, modified with 42 x Thundersky 60Ah in July 2010. Done 194'000km

Last seen: 5 years 2 weeks ago
Joined: Friday, December 1, 2006 - 09:01
Points: 712
Re: Troubleshooting a controller and hub motor

If the short is that big, it should be visible! The controllers I've seen were easy to disassemble.

I had good results and service from a TNC replacement controller for an earlier brushed hubmotor. I don't, however, see a brushless controller in the listing. :(


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