Help! Pas in reverse

Kneebiker

Pedelecer
Mar 8, 2021
50
5
Hello All.

I'm a bit flummoxed. Ive wired up a bafang front hub with kt controller. The pas sensor was a generic one and didn't come in same kit as kt lcd and controller. So the wire colours didn't match nor did the connector.

The pas side is red,blue and yellow. The controller side is yellow , black brown

The only way I can make the thing work is to match pas to contoller like this red/brown, yellow/black and blue/yellow.

Thing is it only makes the motor work if I turn the cranks backwards. Ive tried flipping the magnets and other wiring methods but I cam make anything else work at all

What am I missing ? I feel it must be something obvious !

Thanks
 

AGS

Esteemed Pedelecer
Feb 12, 2023
608
190
C1 changes the pas direction. If your display is set to 0, or 1 or 2, change it to 5 or 6 or 7 and vice versa.

0 and 5 are usually the highest settings
2 and 7 are usually the standard settings
1 and 6 are usually the middle settings
 
Last edited:

saneagle

Esteemed Pedelecer
Oct 10, 2010
7,005
3,241
Telford
Hello All.

I'm a bit flummoxed. Ive wired up a bafang front hub with kt controller. The pas sensor was a generic one and didn't come in same kit as kt lcd and controller. So the wire colours didn't match nor did the connector.

The pas side is red,blue and yellow. The controller side is yellow , black brown

The only way I can make the thing work is to match pas to contoller like this red/brown, yellow/black and blue/yellow.

Thing is it only makes the motor work if I turn the cranks backwards. Ive tried flipping the magnets and other wiring methods but I cam make anything else work at all

What am I missing ? I feel it must be something obvious !

Thanks
On any bike, you reverse direction of a magnet disc type PAS by flipping the magnet disc. If it works backwards, you installed the magnet disc the wrong way up.

KT controller has a setting to respond to the reverse pattern, but it doesn't always work. Try it first, otherwise flip the disc.
 

Kneebiker

Pedelecer
Mar 8, 2021
50
5
C1 changes the pas direction. If your display is set to 0, or 1 or 2, change it to 5 or 6 or 7 and vice versa.

0 and 5 are usually the highest settings
2 and 7 are usually the standard settings
1 and 6 are usually the middle settings
Thanks, I'll find some inx for rhe lcd
 

Kneebiker

Pedelecer
Mar 8, 2021
50
5
On any bike, you reverse direction of a magnet disc type PAS by flipping the magnet disc. If it works backwards, you installed the magnet disc the wrong way up.
Honestly I've tried that. It simply does nothing when flipped
 

Kneebiker

Pedelecer
Mar 8, 2021
50
5
You have C1 set incorrectly.
Thanks for your help. I'm really lost now

Tried every single setting with magnet flipped each way. It only ever works backwards. It's really weird on some settings it works backwards no matter which way magnet ring is flipped!
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
20,981
8,565
61
West Sx RH
Show us a pic of how the sensor is fitted, you may have to rotate the sensor 180 degrees.
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
20,981
8,565
61
West Sx RH
Hello All.

I'm a bit flummoxed. Ive wired up a bafang front hub with kt controller. The pas sensor was a generic one and didn't come in same kit as kt lcd and controller. So the wire colours didn't match nor did the connector.

The pas side is red,blue and yellow. The controller side is yellow , black brown

The only way I can make the thing work is to match pas to contoller like this red/brown, yellow/black and blue/yellow.

Thing is it only makes the motor work if I turn the cranks backwards. Ive tried flipping the magnets and other wiring methods but I cam make anything else work at all

What am I missing ? I feel it must be something obvious !

Thanks
Wiring sequence is correct.
PAS Red /5v , Blue /Sig & Yellow /Gnd.
Con Brown/ 5v, Yellow/Sig & Black /Gnd.

Red or Brown can be 5v , Yellow or Black can be Gnd. When both Yellow and Black are both used then Black is Gnd and Yellow the Sig.
 

saneagle

Esteemed Pedelecer
Oct 10, 2010
7,005
3,241
Telford
Thanks for your help. I'm really lost now

Tried every single setting with magnet flipped each way. It only ever works backwards. It's really weird on some settings it works backwards no matter which way magnet ring is flipped!
The double hall sensor ones only work in one direction. You didn't buy one of those stupid 12 magnet ones did you? If you did, it has to go on the other side of the crank.

The wires are correct when it works backwards. You can't change direction with the wires. 5v and ground power it. They must be the right way round otherwise it doesnhave power. The third wire is the output signal that is in a pattern according to the orientation of the magnets and the direction of their rotation.
 

Kneebiker

Pedelecer
Mar 8, 2021
50
5
The double hall sensor ones only work in one direction. You didn't buy one of those stupid 12 magnet ones did you? If you did, it has to go on the other side of the crank.

The wires are correct when it works backwards. You can't change direction with the wires. 5v and ground power it. They must be the right way round otherwise it doesnhave power. The third wire is the output signal that is in a pattern according to the orientation of the magnets and the direction of their rotation.
Ahh, it's seems I did buy one with 12 magnets. If that's the issue can you recommend me a replacement ?
 

AGS

Esteemed Pedelecer
Feb 12, 2023
608
190
Have you tried fitting it on the chain side? The manual says the controller will work with a 12 magnet pas, but people have had issues.
 
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Nealh

Esteemed Pedelecer
Aug 7, 2014
20,981
8,565
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West Sx RH
That type is designed for the rhs behind the crank wheel. What you can try before binning it or changing side, is to rotate the sensor so the head is at the top and then try it.
 
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thelarkbox

Esteemed Pedelecer
Aug 23, 2023
1,252
385
oxon
Same sensor i use , i can confirm its fitted on the chain side and fitting involves removing the bottom bracket and refitting with the sensor secured behind the bottom brackets external flange (sorry i dont know all the cycling terminology..).. upside down wont make a difference
 
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Nealh

Esteemed Pedelecer
Aug 7, 2014
20,981
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West Sx RH
The orientation of the sensor can change the fwd or bkw signal if it is a single hall sensor, much the same as sometimes reversing the disc face.
 
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Kneebiker

Pedelecer
Mar 8, 2021
50
5
That type is designed for the rhs behind the crank wheel. What you can try before binning it or changing side, is to rotate the sensor so the head is at the top and then try it.
Thanks, sadly didn't work
 

Kneebiker

Pedelecer
Mar 8, 2021
50
5
Thanks everyone. I really don't want to mount chain side. No room plus hassle.

I've ordered a 8 magnet lhs mounted sensor from amazon for 8 quid same day delivery