Help with an electric problem

Clive Belfield

Pedelecer
Oct 9, 2019
28
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My front wheel conversion kit has run faultlessly for a few years but now has developed problems. When I switch it on the display light on the KT880 display comes on but immediately goes out. I have bypassed the display with a jumper connection but on a ride yesterday the system died again. The output voltage from the battery is 40.4 volts. Can anyone recommend a bike shop in Yorkshire where I can get this problem resolved. Thanks.
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
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Probably needs a new battery, 40.4v generally isn't a sign of a healthy battery.
Could be that cell or two has failed or balance is out causing lvc to cut in pretty instantly when you switch on.
 

Clive Belfield

Pedelecer
Oct 9, 2019
28
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Apologies for omitting to say that it is a 36 volt system with the voltage measured after a ride i.e partly discharged
 

Nealh

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Aug 7, 2014
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Ok more info more of a complete story.
Usually there is a wire/connection fault between battery and lcd or the lcd is faulty.
Battery supplies a feed to the lcd which then communicates with the controller.
Double check all wire connectors for a loose connection or wire.
 

Clive Belfield

Pedelecer
Oct 9, 2019
28
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Ok more info more of a complete story.
Usually there is a wire/connection fault between battery and lcd or the lcd is faulty.
Battery supplies a feed to the lcd which then communicates with the controller.
Double check all wire connectors for a loose connection or wire.
Thanks Nealh but in order to test the display I disconnected it using a jumper conection. I only managed to ride for 10 miles before the system shut down. Any help is much appreciated
 

vfr400

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Jun 12, 2011
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Did you bridge the data wires as well as the red and blue power wires? If not, try it like that.

10 miles is a long way to go before a fault showed. It sounds more like an intermittent fault than a systemic one. Check your motor connections at the controller and that the 9-pin connector is all the way in to the line.
 

Clive Belfield

Pedelecer
Oct 9, 2019
28
0
Did you bridge the data wires as well as the red and blue power wires? If not, try it like that.

10 miles is a long way to go before a fault showed. It sounds more like an intermittent fault than a systemic one. Check your motor connections at the controller and that the 9-pin connector is all the way in to the line.
The jumper plug connects Yellow to Black and Red to Blue. Remade off all the motor and power connectors at the controller and still the same problem. The lights on the display come on and go straight off and the motor doesn't turn. Not sure what the 9 pin connector is. Thanks for you help.
 

vfr400

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Jun 12, 2011
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When I run them without an LCD, I always jump the data wires - yellow to green or white. I don't trust those plugs that they supply. I don't think that that will solve your cutting out. it would be different if it were 5 or 10 minutes, but not half an hour or more.

Next time it does it, check to see how hot the controller is. Check the motor connections anyway.
 

Clive Belfield

Pedelecer
Oct 9, 2019
28
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I have redone the connections to both the motor and battery, still the same , LED lights come on and go straight off. Cannot get power to the motor now. The controller was a little warm but as it has always been in the same small bag under the top tube I assumed that this was normal
 

vfr400

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Jun 12, 2011
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The display is probably faulty. It's had water in it or something like that. It works independently from everything else. When it doesn't stay on, it's because the CPU in it can't work. Your motor and controller work, so there's nothing wrong there that could cause the battery voltage to drop, which would be the only other possibility. A replacement panel should fix everything.
 

Clive Belfield

Pedelecer
Oct 9, 2019
28
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When I was on the ride Wednesday I didn't have the display connected I was using the jumper plug and the system shut down. How then can it be the display? Thanks.
 

vfr400

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Jun 12, 2011
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When I was on the ride Wednesday I didn't have the display connected I was using the jumper plug and the system shut down. How then can it be the display? Thanks.
I'm talking about your original problem. Your shutdown could be anything, but I bet when you get a new display, you can ride your bike again.