My first conversion project - Carrera Subway 2

spikey

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Aug 6, 2013
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I tried all that.

When I unscrewed the cable, the plug with 3 pins on the speed sensor itself came off. It looks like that this was meant to be soldered to the sensor so I pretty sure I need a new sensor.
 

trex

Esteemed Pedelecer
May 15, 2011
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you have an LED on the sensor. If the sensor is still working, the LED blinks when the magnet passes in front of it.
 

trex

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May 15, 2011
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then it looks like you need a new sensor.
 

Kinninvie

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Oct 5, 2013
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Teesdale,England
Paul does not have them on his site but I am sure if you e-mail him he would be able to source one(or a couple) for you.
 

spikey

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Aug 6, 2013
77
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Thanks guys, I've emailed Paul about this and hope he has some spare. I contacted BMSbattery and after a lengthy chat they agreed to send me a replacement speed sensor for free but the shipping cost would be $30. :eek:
 

Nealh

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Aug 7, 2014
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West Sx RH
Try woosh !!!
 

Kinninvie

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Oct 5, 2013
907
415
Teesdale,England

trex

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May 15, 2011
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speed sensor is a simple device and can be repaired.
Post a picture for identification.
 

spikey

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Aug 6, 2013
77
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Try woosh !!!
Thanks, I've tried them and they don't have spares, unfortunately. They did suggest as a last resort to use a regular speed sensor and do a diy job to connect them together, but don't know how.
 
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spikey

Pedelecer
Aug 6, 2013
77
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speed sensor is a simple device and can be repaired.
Post a picture for identification.


I've got an old bike computer that has a speed sensor. Could you show me what wires to connect to the Bafang kit.
 

trex

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May 15, 2011
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you've got the 2014 model. The sensor seems to be intact, the fault could be damaged cable. You could spend $30 getting another sensor without result.
Try to measure the voltage on the holes of the socket that this connector plugs into on the motor side. There are three holes corresponding to 3 pins, you only need to locate the ground and +5V. Linking only the 0V and 5V pins to the socket side will let you test the sensor on its own, the LED should blink when the magnet passes in front of it.
 

spikey

Pedelecer
Aug 6, 2013
77
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The part where you can see the pins sticking out on the previous photo has come apart and wires snapped off.
 

spikey

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Aug 6, 2013
77
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Try to measure the voltage on the holes of the socket that this connector plugs into on the motor side. There are three holes corresponding to 3 pins, you only need to locate the ground and +5V. Linking only the 0V and 5V pins to the socket side will let you test the sensor on its own, the LED should blink when the magnet passes in front of it.
So the 3 pins are designated as
1. 0V
2. +5V
3. Speed signal

Is that right?
Would I damage the controller if I got the wires connected incorrectly?
 

trex

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May 15, 2011
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I take it that the $8 covers the sensor itself, not the cable that comes from the motor.
you still have to repair the socket first. Once done, the current sensor may just work.
 

spikey

Pedelecer
Aug 6, 2013
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Yes, $8 for sensor only. The circuit board inside the sensor is covered in epoxy. Did try to fix it but failed. Any ideas about the pin identification.