I was out on my 905se which i have had for the last two and half years and found it to be superb. Suddenly i lost power the the display on the speedo shows o mph even on a fast downhill section the walk throttle and PAS produces no power. After a long 12 mile cycle home without power i decided to remove the cover from the controller. First thing I note is a strong burning smell . The three heavy wires to the motor have melted and also fused to the six way signal cable from the motor. I have cut the damaged cables back and inserted new cables using solder joints and crimps . I now find the throttle works the motor appears to have plenty of torque and turns. The speedo still shows 0 mph if i apply the brake the current on the display increases as i would expect. Turning the pedal produces no power. I have sent email to Wisper. My suspicion is the controller has been damaged or the sensors on the motor are damaged. Has anyone any suggestions which may indicate my next steps?
Wisper 905se problem
- Thread starter JOIG
- Start date
My guess is that a couple of the main motor wires touched. The speedo gets it's signal from the white wire in the white one in the 6-way connector. have a close look at that to see where it's broken. If it's not broken, maybe one of the main motor wires touched it and wiped out the sensor, in which case you'll have to use an external speed sensor with a wheel magnet. You can test it by measuring it's voltage from ground. It should pulse once or 6 times with each wheel rotation at 5v.
Thanks for your swift reply . I shall have a look tomorrow basically the motor wires were welded to the six way connector so your scenario makes sense. I have emailed Wisper as i feel such a catastrophic failure should not happen shortly after my warranty expires. Having said that my dealings with wisper have always been excellent.
Hi it reads as if there was cable damage which caused a short. I am sure we can assist you to resolve. Please contact support@amps.bike and Adrian will look after you.
All the best, David
I have had a look and the white wire is at 4.75v and does not change state as the wheel is turned. I have examined the six way connector and it appears that it is the red and black wires that have been burnt with contact with the motor phase wires. The white wire shows no burning. I cant understand how fitting a magnet and switch will work. If I should expect six pulses per turn one magnet and sensor will only produce one pulse per turn? What do the red and black wires do on that connector ? I wonder if red and black getting excessive voltage has damaged several components within the motor.
Most motors only give out one pulse per rotation on the speed sensor. Anyway, I'm pretty sure that there is a setting in the Wisper LCD to adjust it. You'll have to ask Wisper about that. If your motor gave 6 pulses and you can't adjust it in the LCD, then you need 6 wheel magnets.
There are two types of external speed sensor. The first type have two wires and a reed switch. These are the type you get on cycle computers. If you have an old one, cut the wire at the head unit, or buy a cheap one from EBay and cut the sensor off. You join one wire to the controller white and the other to either any red 5v wire or any black ground - whichever one works because some white wires are held high and pulse low, and some are held low and pulse high. The second type are proprietary ebike speed sensors with a hall sensor and three wires. Connect the signal to white, the 5v wire to any red 5v and the ground to any ground.
There are two types of external speed sensor. The first type have two wires and a reed switch. These are the type you get on cycle computers. If you have an old one, cut the wire at the head unit, or buy a cheap one from EBay and cut the sensor off. You join one wire to the controller white and the other to either any red 5v wire or any black ground - whichever one works because some white wires are held high and pulse low, and some are held low and pulse high. The second type are proprietary ebike speed sensors with a hall sensor and three wires. Connect the signal to white, the 5v wire to any red 5v and the ground to any ground.
I
I have done some more voltage test
Black to Red 4.26v This is correct
Black to White 4.75v this voltage does not change state by turning wheel using throttle or turning by hand. This is incorrect behaviour.
Black to Blue 4.75v drops to 2.14v when using hand throttle turning wheel by hand 0.02 up 4.47 several time for each turn of wheel.[Only when turning backwards?) this is correct behaviour i assume.
Black to Yellow and Black to Green 0v no change using throttle or turning by hand . This is incorrect behavour.
I assume that i have three hall sensors that have blown when the short occurred. I see several videos on YouTube about replacing them. The problem is trying to find the correct type of sensor . Has any one on this forum attempted this ? I still await contact from support at Wisper . I'm not sure if they will have a repair kit to cover this scenario. The motor seems to have SY3626RD474 printed on it . I cant find any info on this type of motor on the internet .
Can anyone help?
You only have three hall sensors. White is the speed sensor. It might only switch once per rotation, so is difficult to test. It might be worth checking again. Something isn't right because you said the throttle works the motor, but with two blown hall sensors, it shouldn't be able to.
Thanks i thought it was strange without hall sensors it should not run. I have checked voltages several times and these are results i get each time. When i say throttle the motor only runs at walk speed this is normal. Does walk mode not use hall sensors? I was speaking with my neighbour who has been running his ebike without speed info for a while . lack of speedo dosn't concern me if it never works again ,its just happened since my blow up. I would i have tested out the PAS voltages and the work as I would expect them. I think i will have to phone Wisper to discuss
Most controllers cannot turn the motor in any way if they don't get the correct hall signals. There are exceptions, and they're sensorless or dual-mode controllers, but I can't say that I've seen one on an OEM bike before. If your motor didn't work, I was going to suggest getting a sensorless controller, which would be cheaper than a new motor.
Try disconnecting your hall connector to see if your motor still runs. If it does, your controller must be dual mode.
Thanks vfr400
I disconnected all three hall sensors as suggested and motor does not run and the display shows a motor symbol. So I then tried connecting each hall sensor one at time . Each time I connect one the motor gives a kick when the throttle is opened . Don't know what that proves. maybe hall sensors are ok? Adrian from Wisper has been in touch and he is sure it is my controller that is the problem . So I have a controller and new cable on order. Time will tell.
OK, your story doesn't make sense. Hall sensors either work or not. If the motor turns with the walk assist, there should be nothing wrong with them.
The lack of speed display is a problem with the speed sensor - either blown sensor or connection fault, but that shouldn't affect the running of the motor.
I think you should check the hall sensor voltages one more time. Do it like this: Switch everything on and measure between black and each of blue, yellow and green while you rotate the wheel backwards by hand.
The lack of speed display is a problem with the speed sensor - either blown sensor or connection fault, but that shouldn't affect the running of the motor.
I think you should check the hall sensor voltages one more time. Do it like this: Switch everything on and measure between black and each of blue, yellow and green while you rotate the wheel backwards by hand.
The new cable and controller arrived from Wisper and i fitted them and i got the same result . I went through my voltage measurements again and the blue cable is the only one that gives a reading satisfactory reading 0.02-4.75v as i turn wheel backwards.The yellow and green give a very short pulse its only very momentary incorrect in my book.
I decided to take motor out and have a look inside . The hall sensors show no visible damage and lift out on a circuit board . I have decided to replace them and have ordered these
https://www.ebay.co.uk/itm/6x-Bipolar-Hall-Effect-Sensor-41F-SS41-SH41-SS41F-Electric-Bike-Motor-Repair/281804272538?ssPageName=STRK:MEBIDX:IT&_trksid=p2060353.m2749.l2649
I sent a message to the seller and he has said these will be fine. I cannot decipher the markings on the sensor. Are these correct? I notice the speed sensor is totally different and is activated by a single magnet on hub cover. I am going the phone wisper tomorrow I dont suppose they can supply the circuit board complete with sensors .
Hall sensors arrived today and fitted I now have correct voltage on all three hall sensors. But i still have same problem motor will only run using hand throttle and only at walk speed. I have an external sensor on order for speed sensor problem . Does this bike need a speed signal to allow the motor to work at anything faster than walk mode ?
Not normally, the speed sensor only affects the speed display and sleep mode engaging every 5 minutes or whatever it's set to.
Pleased to say all working now . I ended up replacing the PAS sensor which got everything working as intended.I still have to try and make something so i can get my now external speed sensor close enough to wheel magnet. Thank to vrf400 for all your help its certainly been a bit of an education for me
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