Help again please

Itsshreck

Pedelecer
Jun 8, 2021
48
1
Hi a couple of weeks I asked where I can buy a pedal sensor
you pointed me in the right direction and iam very grateful
I have only just received it due to being in Spain
i have now fitted it but it is still not working
but what I have noticed there is a button on the control panel and when iam stationary it seems to lurch forward for a split second ( if I press it )
so iam wondering is there some kind of reset procedure ?

I have also disconnected the brake sensor plugs but still no luck

many thanks guys I really appreciate your help
 

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saneagle

Esteemed Pedelecer
Oct 10, 2010
8,498
3,860
Telford
Test to see if it works when you pedal backwards. If it does, flip the magnet disc.

Which pedal sensor did you buy?
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
21,402
8,746
61
West Sx RH
If the above doesn't work then the wire sequence may be incorrect.
Does the Red LED on the sensor blink as the magnets pass ?
 

Itsshreck

Pedelecer
Jun 8, 2021
48
1
Hi guys sorry for late reply

ok just a update
the bike has never been touched at all
so not sure about the wiring being incorrect ( but I could be wrong)
all I have done is change the sensor on the pedal crank not the magnet
because the light stayed on permanent
before it did nothing at all but since changing the sensor it has a brief ( half a millisecond) ) surge
then nothing
i tried disconnecting the brake sensors but that has made no difference
 

Itsshreck

Pedelecer
Jun 8, 2021
48
1
Hi guys re original question I have been struggling with the fault on my bike but a friend who is very clever has just been testing everything and says I need this can you point me in right direction to get this exact one please
Obviously I need to be correct has it is difficult to return things from Spain and very expensive. Thank you
 

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saneagle

Esteemed Pedelecer
Oct 10, 2010
8,498
3,860
Telford
Hi guys re original question I have been struggling with the fault on my bike but a friend who is very clever has just been testing everything and says I need this can you point me in right direction to get this exact one please
Obviously I need to be correct has it is difficult to return things from Spain and very expensive. Thank you
It's a Santroll controller. They're OEM only. Earlier, you said that the walk assist button works. In that case, there's nothing wrong with your controller, so tell your clever friend to look elsewhere for the cause of your problem.
but what I have noticed there is a button on the control panel and when iam stationary it seems to lurch forward for a split second ( if I press it )
The light on the pedal sensor stayed on because it was wired incorrectly. Tell your friend to check the sequence of the wires on each side of the connector. On the controller side, one has 5v, one has continuity to ground, and by deduction the other is the signal wire. You can only get the sequence of the replacement one from the supplier, or you have to cut the connectors off to see the colour of the wires.
 

thelarkbox

Esteemed Pedelecer
Aug 23, 2023
1,559
486
oxon
The sensor led should flash/blink when/as it detects rotation, permanently on would indicate its wired up incorrectly as said above. Probably not doing the sensor much good too.

While its a nasty practice to use a generic type plug/socket like Julet and wire it up in a 'bespoke' way its not unheard of. Opening up the controller box and continuity testing the wires from the pcb connection point to the julet socket is less destructive initially but if the case a chop somewhere is inevitable.. (wire colours will be visible and the pcb may even have helpful screen printing) ..
Dont force a meter probe into a tiny socket and kill it like someone, instead source a sewing pin or needle thin enough not to damage the socket..

google tells me this is a generic pas sensor pinout

 

Itsshreck

Pedelecer
Jun 8, 2021
48
1
Hi guys
thanks for replying I will pass this information onto him and see what he says
much appreciated
 

Itsshreck

Pedelecer
Jun 8, 2021
48
1
Totally conflicted now
Don’t know what to do this the reply from the chap that has looked at it

please understand nothing has ever been touched on the bike from new
Apart from the pedal censer

this was is reply after showing him the feedback I got from you guys

you can't wire it in an incorrect way. if it's not this box, it's the motor and you can forget the bike.
 

saneagle

Esteemed Pedelecer
Oct 10, 2010
8,498
3,860
Telford
Totally conflicted now
Don’t know what to do this the reply from the chap that has looked at it

please understand nothing has ever been touched on the bike from new
Apart from the pedal censer

this was is reply after showing him the feedback I got from you guys

you can't wire it in an incorrect way. if it's not this box, it's the motor and you can forget the bike.
You can't wire it the wrong way yourself, but you can buy one that's wired the wrong way. Maybe find another clever mate, who's prepared to listen and do valid tests.

Here's how you test an ebike:
1. Measure the voltage at controller's battery connector. Obviously should be battery voltage. 36v - 42v for a 36v battery would be an acceptable range, but if you've fully charged the battery and it's less than 41v, it needs some sorting.
2. Measure the voltage on the 5v rail. You can measure that between any ground (black) and any of the reds going to the PAS or motor halls. It should be around 5v. In your case, probe the three pins on the PAS connector to see which one is 5v - if any.
3. You don't need to do this one unless you have a throttle. Check throttle signal wire voltage on it's connector while connected. it's the wire that's not red or black on the throttle connector. Should give about 1v to 4v when you twist the throttle. If there's more than one wire, your meter will find it. It's the one that's between 1v and 4v, assuming that it works.
4. Check that the pedal assist sensor is pulsing. Measure the PAS signal wire while turning the pedals slowly. Should pulse 5v on and off every time a magnet passes the sensor. The signal wire is the one that's not red or black. This test is very tricky when you have moulded connector. Best is to take the controller out of its aluminium case and test where the wire is soldered to the PCB.
5. Check the motor hall signal wires (blue green and yellow) on the motor connector at the controller. They should each pulse with 5v going on and off as you rotate the wheel BACKWARDS. Again, difficult to do if you have moulded connectors. You need to show what you have.
6. Mosfet test. Disconnect the motor cable and battery from the controller. Measure the resistance (200k scale) between the red battery connection and each of the three phase wire connections, then repeat with the black battery wire. Each set of 3 readings should be the same as each other and in the range 7K -24K. Though can be higher as long as they're all the same. Due to the capacitor across the battery wire, you can get a constantantly changing measurement while it charges. In that case, try swapping your probes round. Even though can be a moving result, the only important thing is that all three move in a similar way.
 
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