Problem with throttle

UrbanPuma

Esteemed Pedelecer
Sep 11, 2007
634
41
Hi all,

I have a problem when using my throttle...the motor switches to what sounds like a high gear (whirling) without stopping when throttle hits maximum speed and can only be stopped if I apply the motor brake. Normally when I let go of the throttle the wheel slows to an eventual stop, but not in this case.

The multimeter shows following readings when idle:

Signal (green) + ground (black) = 3.82
Positive (red) + ground (black) = 19.79

These readings don't appear to be normal. What do you think could be the issue?

Any help will be much appreciated.

Thanks in advance
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
20,131
8,230
60
West Sx RH
One assumes it is a faulty controller , a regulator fault if seeing near 20v on the 5v line.
 
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UrbanPuma

Esteemed Pedelecer
Sep 11, 2007
634
41
Ok thanks. What solution would you recommended to fix the issue?
 
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Bonzo Banana

Esteemed Pedelecer
Sep 29, 2019
740
432
Repair the controller or replace it but you haven't given any details of the ebike or the controller etc. It could be a known issue for that controller or ebike if pre-built. If you know a component is faulty its good to replace as soon as possible as faults could be stressing other components.
 

UrbanPuma

Esteemed Pedelecer
Sep 11, 2007
634
41
The bike had been working perfectly until I had the phase wires changed from bullet to MT60 connectors and the person damaged something in the process - could the problem be caused by the wires in the connection?
 

AGS

Esteemed Pedelecer
Feb 12, 2023
466
141
It is possible that the fault with the wiring that occurred requiring the phase wire connectors to be changed has damaged the controller.

The voltage supply to the throttle should only be +5 volts (Red to Black). You are reading 19.79 volts which is way too high. This means the voltage on the throttle signal wire is also way too high. This will cause the throttle to be essentially fully open all of the time.

This is confirmed by the symptom that you are describing with 3.82 volts on the throttle signal wire at idle, hence the motor spins at idle until you cut the motor using the brake.

So it looks like the 5 volt regulator has blown inside the controller and other damage may have occurred within the controller.
 
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UrbanPuma

Esteemed Pedelecer
Sep 11, 2007
634
41
It is possible that the fault with the wiring that occurred requiring the phase wire connectors to be changed has damaged the controller.

The voltage supply to the throttle should only be +5 volts (Red to Black). You are reading 19.79 volts which is way too high. This means the voltage on the throttle signal wire is also way too high. This will cause the throttle to be essentially fully open all of the time.

This is confirmed by the symptom that you are describing with 3.82 volts on the throttle signal wire at idle, hence the motor spins at idle until you cut the motor using the brake.

So it looks like the 5 volt regulator has blown inside the controller and other damage may have occurred within the controller.
Thanks, yes I think this is spot on. Is it repairable or should I just buy a new controller?
 

AGS

Esteemed Pedelecer
Feb 12, 2023
466
141
It could be repaired, but the cost and hassle involved means that it may be better to buy a new controller and possibly a new display.

You haven’t said what make the controller, display and motor are.

If you can find out the information and maybe post a few photos, someone will be able to advise you on the best course of action.
 

UrbanPuma

Esteemed Pedelecer
Sep 11, 2007
634
41
It could be repaired, but the cost and hassle involved means that it may be better to buy a new controller and possibly a new display.

You haven’t said what make the controller, display and motor are.

If you can find out the information and maybe post a few photos, someone will be able to advise you on the best course of action.
The bike is Powacycle Puma https://www.e-bikesdirect.co.uk/brands/powacycle/powacycle-puma-lpx-folding-electric-bike

1. Controller is Hao Yueh LMK201
2. Motor is ANG (zoom in picture to double check name as I'm unsure of full name)
3. Display is the Powacycle display

Pictures attached. Thanks
 

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AGS

Esteemed Pedelecer
Feb 12, 2023
466
141
I think a KT24 controller coupled with an LCD03 or maybe a cheaper LCD05 display will be a good replacement.

Here are a couple of links to a reputable UK dealer. Although you can get them cheaper from other sellers on ebay/Amazon.

Controller

Displays


You just need to make sure the controller fits into your housing and some rewiring of connectors may be necessary to interface the cables to your bike.
 

UrbanPuma

Esteemed Pedelecer
Sep 11, 2007
634
41
Great, many thanks AGS. I had a job getting the controller out, so fingers crossed new ones fit. I have the tools to fit new connectors which are great. Thank you
 

UrbanPuma

Esteemed Pedelecer
Sep 11, 2007
634
41
I think a KT24 controller coupled with an LCD03 or maybe a cheaper LCD05 display will be a good replacement.

Here are a couple of links to a reputable UK dealer. Although you can get them cheaper from other sellers on ebay/Amazon.

Controller

Displays


You just need to make sure the controller fits into your housing and some rewiring of connectors may be necessary to interface the cables to your bike.
Just a few more questions. Would the LCD4 display be suitable too? Also, what does it mean by speed set on the controller? Will it alter they way the PAS works because at present it is one speed and resistance is added using the gears and there's no throttle restriction such as walk assist mode as it's a pre-2016 made bike?
 
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saneagle

Esteemed Pedelecer
Oct 10, 2010
4,181
2,077
Telford
Just a few more questions. Would the LCD4 display be suitable too? Also, what does it mean by speed set on the controller? Will it alter they way the PAS works because at present it is one speed and resistance is added using the gears and there's no throttle restriction such as walk assist mode as it's a pre-2016 made bike?
It might be worth putting a new battery in your meter or testing a known DC voltage with it before spending a load of money. A flat battery causes most meters to read high.

Controllers have a safety system that will not allow power until your throttle signal corresponds with the zero throttle position (around 1v), so your bike wouldn't work at all if the idle signal were 3.8v, and 19.8v would probably be enough to kill your controller's CPU, all the motor hall sensors, the throttle and the pedal sensor, so not very likely, though not impossible.

Your problem sounds like cruise control engagement that happens when you hold the throttle still for 5 seconds or whatever. Normally that only happens at full throttle because you're bumping about a lot. Test it with the wheel off the ground to see if you can get it to engage at half-throttle. Hold the hrottle perfectly still for say 10 second, then let go.
 

UrbanPuma

Esteemed Pedelecer
Sep 11, 2007
634
41
It might be worth putting a new battery in your meter or testing a known DC voltage with it before spending a load of money. A flat battery causes most meters to read high.

Controllers have a safety system that will not allow power until your throttle signal corresponds with the zero throttle position (around 1v), so your bike wouldn't work at all if the idle signal were 3.8v, and 19.8v would probably be enough to kill your controller's CPU, all the motor hall sensors, the throttle and the pedal sensor, so not very likely, though not impossible.

Your problem sounds like cruise control engagement that happens when you hold the throttle still for 5 seconds or whatever. Normally that only happens at full throttle because you're bumping about a lot. Test it with the wheel off the ground to see if you can get it to engage at half-throttle. Hold the hrottle perfectly still for say 10 second, then let go.
It was happening intermittently, when turning to half throttle - on the old throttle it switched sound and started spinning at maximum speed after a few revs and also at full throttle until I applied the motor brake.

I think the battery is fine because the bike works and I pedaled in PAS mode, but maybe because that is low speed the switch didn't kick in.

It's a fairly old bike and I've never heard of cruise control on it before. How would cruise control be set up for this bike?
 
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blu joe

Finding my (electric) wheels
Oct 6, 2023
17
-1
Could have the cruise controll wires still connected so the motor keeps going on cruise, the cruise wires are usually black and blue and the wires are likely bridged with a connectot, remove it