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In my E-bike, sensor wires has come out from the left side brake lever. Please see attached photo from link below. How do I re-connect wires to sensor. How do I get access to sensor terminals? Do I have to buy a new brake lever with sensor cable attached?

enter image description here

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  • For some models it's possible to replace the sensor and wiring without replacing the brake lever. I've done this with Tektro but finding spares was hard.
    – Chris H
    Jan 11, 2022 at 10:43

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Based on the photo, there's a small knurled plastic ring around the cable. Try unthreading that and the switch should come out.

Then you'll need to strip the wires and solder to the switch, and provide mechanical support using heatshrink etc.

When you refit the switch, make sure the wires are not being pulled. I'd suggest adding more zip-ties to hold the wires to the brake cable for support.

Do take progress photos and add them as an answer of your own. If you feel this is beyond you, anyone handy and competent with electrics/wiring should be okay to do this.


The purpose of this sensor is to cut off the motor if you start braking. If you're comfortable with letting off the throttle, or coasting to brake, then the motor should shut off any assistance.

The sensor switch is probably a "normally closed" and will open when you press the brake lever. So to get the bike working temporarily you could bare and twist the two wires together.

Your last resort is to buy a new left-hand brake lever with a sensor. Also, check the right-hand lever and make sure the wire is not under strain now.

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    Thank you Criggie for prompt reply. I removed the black colour small knurled plastic ring but switch won't come out. Jan 12, 2022 at 0:49
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    my best option is to twist the two wires together and ride. When I brake, stop pedalling which will stop the motor. Later I will buy a left brake lever and join the existing wires to new brake lever wires as I do not have access to other end to remove the existing wires completely and connect the new wires. Jan 12, 2022 at 1:19
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    @WimalPerera the downside of the is if you shift gears while timing a gap in traffic, the pedalling to change gears will cause the motor to kick in. When I borrowed an ebike with a broken cable to one brake, I had to get into the habit of always using both brakes
    – Chris H
    Jan 12, 2022 at 9:04
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    The fault I saw was that the manufacturer had cable-tied the wire to the brake cable to relieve strain, really close to the switch. That worked until the barrel adjuster on the brake lever was used for its intended purpose a couple of times. And the switch could be NO or NC. It's a logic input to the motor controller rather than necessarily part of a fail-safe circuit. I still reckon the switch should come out somehow.
    – Chris H
    Jan 12, 2022 at 9:08
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    @chris Noted your comments. I am in contact with e-bike local supplier to direct me to their recommended service shop to have a look. Bike shops near me won't look at it as make of my bike was not sold by them. Jan 12, 2022 at 21:46
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I faced same problem and fixed it.

As per this picture, I reconnected two wires with solder.

connect two wire

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