Bad speed sensor in my Lectric XP

Alan S

New Member
Region
USA
Hello everyone, I have a 500w rear hub motor off a 2020 Lectric XP. My motor stopped working after 80 miles. The motor is under warranty and Lectric is providing a new one. The motor is currently out of stock so I’m on hold for now. Lectric told me that the motor has a bad speed sensor. Being a lifelong DIY guy. I started researching and decided to pull it apart and replace the three hall sensors. Didn’t know how to test them so I replaced all three. Of course I wasn’t 100% sure which type of hall sensor I needed. Reading what I could find, I think the Honeywell bipolar that I got were right but that’s questionable. Anyway after replacing them it was still a no go. It’s possible that my soldering job to the circuit board is less than perfect but I don’t know for sure because I don’t know how exactly to test the hall sensor. I’ve looked on YouTube and yes I have a voltage meter but I’m not sure how to use it. I’ve found a diagnostic tool on Bolton ebikes for $30 that might be what I need but I’m hesitant because I’m not sure it’s applicable. None of my local bike shops want to touch it and at $80 an hour service charge I’m told it’s more cost effective to just buy a new motor. Lectric doesn’t sell their motor. And yes I’m getting a new one from my warranty. I’m rambling. I really don’t want this motor to go in the trash when I believe the fix for it is really very simple. Maybe That’s my misperception. Seeking enlightenment in Austin Texas.
 

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goldconch

Active Member
@Alan S will Lectric not accept back the lousy one to refurbish themselves? Maybe EBR vets @AHicks @harryS might have some guidance or suggestions? Any branding inside the hubmotor to identify it's part catalogue?
 

harryS

Well-Known Member
You can easily test the Hall sensor with those diagnostic testers if it has the right plug. If you can wait a month, order it off ebay for $13.

Speed sensor shouldn't disable a motor, but a Hall sensor will. You could have installed the new ones backwards.

Here's what to do. Set meter so it can read 5 volts, Power up bike with access to the five wires, red. black, yellow, green, blue. Might be tricky with the 9 pin plug.
-Check red to black with meter. You should get 5 volts.
-Then check yellow to black. It will flip between 0 and 5 as wheel turns.
-Same with blue to black, and blue to black,
-I see the speed sensor in your photo. That's the white wire. Test that too,

If you cannot access the wires, do it with the circuit board exposed. Since you cannot turn the motor, bring a magnet next to the sensors,

Does the Bolton tester connect to your motor plug? If it doesn't, you can buy a 9 pin extension cable and cut it open so you can clip the leads to the relevant wires. If you need to do that, uou can buy the tester for $13 on ebay, Cable is the same price too. Too bad it will take a month from China.
 

Alan S

New Member
Region
USA
Embarrassed to say but can you post a pic showing what settings I need to have my volt meter on. And yes it’s more than tricky figuring out wire colors on 9 pin plug. Can I plug the motor into the controller and turn the bike on and then what. Can I touch the wires on the circuit board with volt meter and turn motor by hand? Do I touch the red volt meter probe to the blue green yellow and red wires with the black probe on black wire while slowly turning the magnets? I’m clueless and I know it’s hard to explain in a text. Thanks for your patience
 
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Alan S

New Member
Region
USA
once I know what settings to use on my multi meter. Then plug in motor and power it up. Then can a put the multi meter leads directly on the wires where they are soldered on the circuit board? where do I place the black/red leads of the multi meter?

wou you consider letting me send you my motor and you try to diagnose/repair it. I’m willing to pay up to $200
 

harryS

Well-Known Member
Your meter is set right on 20V. Black probe on the - terminal on that circuit board. Red probe in turn to +. It will show you close to 5 volts. Then test A, B, C, SP.

Nope, Not interested in the work. You got the motor apart and you soldered in a new sensor. You wil be fine.