Battery died suddenly

You should check whether the controller is powering up. Locate the throttle connector, a flat 3 wire connector that has red, black and blue wires per the KT documents. Stick some thin probes into the red and black positions with the throttle unplugged. You ought to see about 4.5 volts when the display powers up.

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If you get the voltage, the controller probably should work unless the LCD3 somehwo shut it down.

The next step would be to try running the controller without a display, It's described here. The little jumper in the discussion is furnished by KT when you buy a controller,


How it's wired is also in their wiring info shown below. You connect the blue wire and red wire together. The red is battery voltage and applying 48V to the controller turns it on. Tying black to yellow grounds out the controller's data input. It's not becessary. I've started my contllers with only the blue-red jumper. Just be careful, It;s battery voltage and if you touch 49V to any of the other three pins, the controller blows up.

You can always snip off the female connector from the display harness, male the two connections and repair it later if the display is needed. If I could find my official KT jumpers, I must have four or five of them, I'd send you one.

With the jumpers in place, a working controller will have an active throttle. Then you know you needed a new display,

KT-Jumper.jpg

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You should check whether the controller is powering up. Locate the throttle connector, a flat 3 wire connector that has red, black and blue wires per the KT documents. Stick some thin probes into the red and black positions with the throttle unplugged. You ought to see about 4.5 volts when the display powers up.

View attachment 174405

If you get the voltage, the controller probably should work unless the LCD3 somehwo shut it down.

The next step would be to try running the controller without a display, It's described here. The little jumper in the discussion is furnished by KT when you buy a controller,


How it's wired is also in their wiring info shown below. You connect the blue wire and red wire together. The red is battery voltage and applying 48V to the controller turns it on. Tying black to yellow grounds out the controller's data input. It's not becessary. I've started my contllers with only the blue-red jumper. Just be careful, It;s battery voltage and if you touch 49V to any of the other three pins, the controller blows up.

You can always snip off the female connector from the display harness, male the two connections and repair it later if the display is needed. If I could find my official KT jumpers, I must have four or five of them, I'd send you one.

With the jumpers in place, a working controller will have an active throttle. Then you know you needed a new display,

View attachment 174407
Thank you so much for the info. I'm learning a whole lot from this process. I will check voltages. I was looking at the wiring at the controller and accidentally touched the controller box to the battery terminals on the bike and got a spark. The battery is not installed so where is this juice coming from? Thanks again.
 
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You should check whether the controller is powering up. Locate the throttle connector, a flat 3 wire connector that has red, black and blue wires per the KT documents. Stick some thin probes into the red and black positions with the throttle unplugged. You ought to see about 4.5 volts when the display powers up.

View attachment 174405

If you get the voltage, the controller probably should work unless the LCD3 somehwo shut it down.

The next step would be to try running the controller without a display, It's described here. The little jumper in the discussion is furnished by KT when you buy a controller,


How it's wired is also in their wiring info shown below. You connect the blue wire and red wire together. The red is battery voltage and applying 48V to the controller turns it on. Tying black to yellow grounds out the controller's data input. It's not becessary. I've started my contllers with only the blue-red jumper. Just be careful, It;s battery voltage and if you touch 49V to any of the other three pins, the controller blows up.

You can always snip off the female connector from the display harness, male the two connections and repair it later if the display is needed. If I could find my official KT jumpers, I must have four or five of them, I'd send you one.

With the jumpers in place, a working controller will have an active throttle. Then you know you needed a new display,

View attachment 174407
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I'm getting a little over 2.2 volts at the controller when I power up the display. ? I will go ahead and jump the display connector now. I've bypassed the display but not sure I did it properly. I jumped the red and blue and with the connector connected, the display turned on but I still didn't get a throttle response. I will order a display. Only thing left is the motor. Please don't let it be the motor.
 
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No disrespect @canadmin.
I honestly think you deserve a new ebike.
My best advice.
Try to fix something that is probably beyond fixing?
I will bite the bullet. Not sure what this old Chinese saying means.
My point is bite the bullet man.
I agree, I do deserve a new bike. Should I send you my address for the delivery?
 
Seems like the controller is fried. I'd hold on the display til you try the new xontroller.,
 
Seems like the controller is fried. I'd hold on the display til you try the new xontroller.,
Are you thinking that the voltage from the controller is too low? Are the values you mentioned a minimum? New controller is on its way. So is a new display. Like I said, I like spare parts. It will take some time to get the parts from Amazon but I will update you after I install the new one. Cheers!
 
If you didn't get 4.5V on the throttle, the controller is probably toast, The same 5 volts powers the data lines to/from the LCD3, any pedal sensors, and also the motor sensors. It could be amy of the latter units loading down the supply

While waiting for a new controller, I suggest you find the white rectangular connector with six wires that goes to the motor. Unplug it. The red/black wires are +5V. Check it too. That voltage should also be low. If it's not , you get where I'm going,
 
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If you didn't get 4.5V on the throttle, the controller is probably toast, The same 5 volts powers the data lines to/from the LCD3, any pedal sensors, and also the motor sensors. It could be amy of the latter units loading down the supply

While waiting for a new controller, I suggest you find the white rectangular connector with six wires that goes to the motor. Unplug it. The red/black wires are +5V. Check it too. That voltage should also be low. If it's not , you get where I'm going,
I checked the red to black wires and did not get 5 volts.
 
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