Please Help, post-crash poblems

BustedBike

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Apr 23, 2022
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I know nothing about Ebikes and only basic DIY type knowledge of anything, so please be patient and reply like I am a moron.

Short story version, my son's friend more or less stole my sons 6 month old ebike and totaled it in a crash against a metal roadside barrier. Luckily he is ok except for some nasty road rash. Some friend, right?

Now the bike... bent rim, slightly offset front forks, and alot of scuffing on the handle bars, grips, and gear shifters, and the electronics are not working properly. I got the rim true and aligned the forks, but the electronics got me stumped.

Here is what I know so far... the display turns on and seems to work normally. It lights up and allows you to change through the assist settings, but the motor does not engage. Neither pedal assist or the throttle work. I have changed the thumb throttle as it looked pretty scuffed, but that made no difference.

I know it's not battery related as we have an extra battery and have tried both. Also, a weird little thing I found by accident, if you have it on and unplug the throttle connector, when you plug it back in it engages the motor fully. I found this out by mistake after changing the throttle and the new one wasn't working either. I unplugged it to make sure the pins weren't bent and when I plugged it back in, the bike tried to take off. While the motor was going, I toggled through the assist modes and noticed the motor responded by slowing down and speeding up, but the only way to stop it was to turn the power off.

This tells me the motor works, but is either stuff on, or stuck off. There is no control over this. The control module appears to be the only thing on the handle bars no scuffed though.

This is the bike in question: Ancheer 21 speed electric mountain bike
https://www.amazon.com/dp/B08DX68T65/ref=redir_mobile_desktop?_encoding=UTF8&aaxitk=c633901f4cf7e01eac7fcd5394b7a76e&hsa_cr_id=6563802270801&pd_rd_plhdr=t&pd_rd_r=1a0f9ac8-c4d8-4db3-86f7-f2911e2525f4&pd_rd_w=pOvUm&pd_rd_wg=VHZvY&ref_=sbx_be_s_sparkle_lsi4d_asin_0_title&th=1
 
Also forgot to include, I think I eliminated it being related to the sensors in the hand brakes. I took one out and noticed if the button is pressed when it is turned on, the display actually has an error code. When they are both in and connected, the code goes away, so they seem to working properly.
 
The original throttle or throttle wiring may have been the issue. So it could just be the wiring order if you throttle plug. Can you share a photo of the plugs and wiring, both on the throttle side and controller side?
Poor or incorrect ground wiring can cause the symptom, so pics may help folk see what you’re dealing with. Good new is that it can probably be fixed easily.
 
Yes, usually a broken ground wire in a throttle will cause full throttle operation with no control over it.

Since it didnt' work at all at first, it could just be that, or it could have other wires on the throttle that are damaged somewhere.

Usually it fails at the exit of the throttle plastics, or the connector (any part of it) between the throttle and controller, but with a crash it could be in the cable itself if it got pulled on or twisted or pinched, and since you've changed the throttle the most likely problem is between the connector and the controller, or the controller side of the connector.

If the PAS doesn't work either, it is probably the same type of failure, with the most likely point being somewhere both throttle and PAS cables / connectors come together on their way to the controller. But it could just be a dislodged magnet ring or sensor bracket near the pedal chainrings.
 
I believe this bike has the controller inside the battery cradle, with a harness that goes to the handlebars with a connector for the display, throttle, the two brakes, and maybe the head light?

At least you know the motor connections are fine. Throttle is a three pin device, +5V, Ground, and sensor output. If the ground is broken. as you were told by amberwolf, the controller goes full throttle. So there is some kind of wiring issue with the harness.

There will be a sensor for the pedal assist around the pedals. It with either be a one piece unit like this. EIther works or it doesn't, but have seen them slip and not even turn. The PAS sensor will be a separate cable going into the controller and you should see it down by the pedals.

type2.jpg|

Or it will be a separate magnet disk and sensor. WIth these, sometimes the magent moves too far from the sensor.

P1630309.JPG
 
Thanks for all of the replies. After reading them, and a little search on google I can explain the set-up better.

The bike has a 1T4 julet wire harness. One yellow line to the throttle, 2 red lines to the brake sensors, and one green to the controller. I followed the line the best I could until it enters the bike frame and again when it comes out. I just inspected it closer and did find one spot of damage where it comes out of the frame on the line that goes to the throttle. It looks like it was pinched, and has a small tear almost like a puncture but I can't tell how deep in it goes.

I've ordered the wire harness and will know if it fixes it in a few days. Would a damaged throttle wire affect the pedal assist though? Or am I looking at 2 separate issues?

I checked, and it appears to have the same sensor docw009 posted a picture of, with the same yellow connector. It is on the crank of the pedal, and while I can slightly wiggle it, it doesn't seem that it moved away from the bike at all, so I think the spacing should be ok...?
 
If the throttle line was damaged, it could trigger an error condition that turns off the power. You might try unplugging the throttle and see if the PAS works.
 
BustedBike said:
Short story version, my son's friend more or less stole my sons 6 month old ebike and totaled it in a crash against a metal roadside barrier.
[...]
This is the bike in question: Ancheer 21 speed electric mountain bike

Oh jeez. The dumb kid did you and your son a favor.

Just like I tell folks about their cheap and horrible department store pedal bikes: Enjoy this thing for as long as it works well enough to make you happy. But DO NOT sink any real money or lots of time repairing it. It's just not worth it. Put away whatever it would cost to nurse it, and use it to get a better bike. Doesn't even have to be more expensive-- it can be a used bike you scrounge for free. But let it be something that wasn't originally built for landfill.
 
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