Help Needed; New e-motorcycle busted, motor not working

RevyExt

1 µW
Joined
Nov 21, 2022
Messages
2
Location
Kutno, Lodzkie, Poland
Hello,

A few months back I bought an electric motorcycle from China. And surprise, surprise it wasn't working from the start.

I don't even know where to start, so my post might be a lil bit messy, and I hope it's in the right thread, as I don't really know much about technical aspects of electric vehicles, their troubleshooting and repair.

The main problem: when you turn the key, everything lights up, everything seems to work, break lights etc, but when you turn the throttle the electric motor doesn't work.

In the papers that I got the model and make is: Dongma DM01
On the Made-in-China site, that I bought it from it was Trigo/Triuni Ducalon

The controller is prolly some kind of Fardriver, but it's been rebadged.

The seller-guy from the manufactory that I bought it from and their engeneer tried to help me with it, but they tried really hard to do it without sending me anything.

I took it apart, we checked all the fuses and wireing and it all seems fine.

We came to this conclusion: When you turn the ignition on on the dashboard it should show P for Park. But on mine it doesn't.
The question is: what's at fault? Is it the throttle, controller or the electric motor?

The Chinese sent me bluetooth dongle to attach to the controller so I could connect to it via phone with fardriver app. But when I try to connect to it, it endlesly says that it's connecting. I tried it on multiple ocasions, on multiple phones, and it just doesn't connect. I don't know if it's a wrong adapter or what's going on. Also when you try to move the wheel with motor with your hand it moves, it gives you some resistance, but it moves, it's not locked, if that's of any help.

Before you ask me: "Why didn't you send it back?" It's problematic to now send it from Europe to China, and I didn't want to even bother.
"Why don't they help you anymore?" The seller-guy contacted me a while back that they changed their internal policies due to covid policies and won't be able to officially help me, as I've ordered only one bike. And now they can provide support for bulk sales. So they left me on ice.
"Why not send it to some repair service in your country?" Believe me, I tried. There are not many of them, and the ones I managed to contact didn't want to have anything to do with a chinese motorcycle that wasn't bought from them or in my country"

I'm open to answer any questions you may have. I really want to finaly fix it, I'm just tired of this situation and just want to get through with it, but I also don't want to just go and outright buy a new controler or motor if I'm not sure what's wrong with it. Things like this are expensive here in Poland.
I hope it's somewhat understandable.
Also I have some videos and photos of it from conversations with the Chinese on my other phone. I'll try to download them and post here.
 
Tere is a huge thread on here about far driver controllers, and the thing I saw mentioned a few times is that there are 2 different Bluetooth dongles.
First thing to check would be all connectors, if they are plugged in, and check the pins themselves etc.
I could help you over the phone to check basic things with a multimeter if you like.
 
RevyExt said:
The main problem: when you turn the key, everything lights up, everything seems to work, break lights etc, but when you turn the throttle the electric motor doesn't work.

Did it ever work correctly?

If it did, then what happened between the time it worked and the time it didn't?


The question is: what's at fault? Is it the throttle, controller or the electric motor?

What voltage range does the throttle signal read, from all the way off to all the way on?

The motor probably has hall sensors, you can test these as a source of a motor problem; we can determine a good way if you want to do this.

A misprogrammed controller could appear broken, or a faulty sensor (like a kickstand sensor, ebrake, etc) could prevent it from operating the motor.
 
amberwolf said:
Did it ever work correctly?

If it did, then what happened between the time it worked and the time it didn't?

I believe it did. It has 15 kilometers on it.

What voltage range does the throttle signal read, from all the way off to all the way on?

The motor probably has hall sensors, you can test these as a source of a motor problem; we can determine a good way if you want to do this.

A misprogrammed controller could appear broken, or a faulty sensor (like a kickstand sensor, ebrake, etc) could prevent it from operating the motor.

I don't know about the voltages on the throttle itself. I know that there's 0 volts on all of the cables that go out of controller to the engine when you turn the throttle.

If you explain to me, how to find and check the Hall sensors I'll make sure to check them as well.

eee291 said:
Tere is a huge thread on here about far driver controllers, and the thing I saw mentioned a few times is that there are 2 different Bluetooth dongles.
First thing to check would be all connectors, if they are plugged in, and check the pins themselves etc.
I could help you over the phone to check basic things with a multimeter if you like.

Thank you. According to the fardriver wiring sheet, everything seems to be connected as should. But I'll make sure to check everything with multimeter this time. If I have any problems I'll make sure to contact you.
I was wondering about the dongle too. It's hard to tell tho which one I should be using, the controller is rebadged. I can't find the pic of it that I've taken a while back. I'll take a new one and send it today, as my bike's in my grandparents garage 7km away from me. The charms of living in a flat in the middle of a town.

I'll attach some videos I've sent to the Chinese. They are.... yeah, you'll see. And these made me remember: when you use your kickstand and brakes, the stop lights turn on and off for both of them, which is as It should be. But the Chinese told me that when you use your brakes it should show on the dashboard that you're pressing a break, but it doesn't. As a matter of fact, nothing really shows up on the dashboard.

It seems you cannot attach mp4 files, so I'm adding a gdrive link to them:
https://drive.google.com/drive/folders/1UONCu1BjS2eS2JDVEUyTqcDG_tSvPAll?usp=sharing
 
The main problem: when you turn the key, everything lights up, everything seems to work, break lights etc, but when you turn the throttle the electric motor doesn't work.
Are the lights powered thru another power source and not the controller.

May need to keep a check list of what you have checked and any voltages. May need it working with different groups of people. As not to repeat any and get to a solution.
If the throttle has no voltage then may need to check were it just comes out of the controller.
 
There are a number of safety features that can lock out the power. Brakes, throttle voltage, battery voltage, hall sensor signals, etc. I would start by measuring the throttle signal voltage. If there is a kick stand switch, check that. The brake switches can often be easily unplugged just to eliminate those. Hall sensor signals are a little harder to measure depending on the connector style. Sometimes you need to use a pin or skinny solid wire to slide into the back of the connector to get a measurement. Unplugging and reconnecting all connectors (and visually examine the contacts) is a good thing to try also.
 
RevyExt said:
amberwolf said:
Did it ever work correctly?

If it did, then what happened between the time it worked and the time it didn't?
I believe it did. It has 15 kilometers on it.
That is an odd answer.

Was it purchased used? Or new? Who rode it for 15 kilometers? What happened to it between the time they rode it successfully, and the time it stopped working, for them or for you? If you don't know any of that info, then:

Did it work *for you*? If it did not work at any time *for you*, or in your presence, then that can be considered to have never worked.

Did anything happen to it between the time you received it, and the time you first powered it on to find the problem you have now? If so, what?

I know that there's 0 volts on all of the cables that go out of controller to the engine when you turn the throttle.
Which specific cables? There are usually many:
--3 thick phase wires to motor
--5 thin hall wires to and from motor
--sometimes multiple thin sensor wires to/from motor
The above are often inside a single cable.
--2 thick battery cables (and one thin keyswitch/ignition wire in many cases)
The above may be in a single cable or all three separate wires.
--5 (or more) thin wires to a display (when there is no KSI wire it's in this display cable instead)
The above are often inside another single cable.
--2 (or more) wires to each brake sensor
The above are often inside another pair of cables, one to each brake lever.
--sometimes multiple thin wires to other sensors like kickstand, etc, or other functions
The above could be in any number of cables.

If *none* of those cables have any voltage, it means your controller is not actually turned on (or is broken), and not supplying 5v as it should. If there is no voltage on the battery wires either, it means the controller is not connected to the battery--either a connector or wire fault, or it uses a contactor or fuse or breaker that is not allowing the connection for whatever reason.

If you get voltage on the battery wires, and there's no KSI wire, and the display connector (while plugged into the display with the display turned on) has battery voltage on only one wire, then the display may not be turning the controller on, because it should be supplying battery votlage back to the controller when it's on, to do that.

There are other possible combinations of If this Then that results, that depend on the exact system setup.

So, to provide proper testing steps, we need to know exactly which wires you have, and where they go, and what voltages you got on any of them that you have tested, and whether they were connected or not when you tested them.


I don't know about the voltages on the throttle itself.

I highly recommend testing those, with the throttle connected to the controller. The below assumes you have three wires to the throttle. If there are more, or less, everything may not apply.

Make sure the bike is stable with the motor wheel securely off the ground, and is not able to touch anything, so if your testing starts it spinning, it won't take off on you or hurt anything.

1 Set your multimeter to 20DCVolts.
2 Place the black lead from its' ground/common pin to your battery's negative connection.
3 Turn on the bike, if it isn't already.
4 Place the red lead from it's V pin to the first throttle wire.
5 Note down the reading you get, then turn the throttle while watching the meter display, and note down how the reading changes, if it does, and the reading you get at full throttle.
6 Repeat step 4 for the next throttle wire, and step 5, until you run out of throttle wires.
7 Post all of the results in this thread.

One wire should read nothing and never change. That's ground, electrically the same as the battery negative.

One wire should read 5v and never change. That's the throttle power supply.

One wire should start at nearly 0v (usually around 0.8v for a hall throttle) and change as you turn the throttle until it reaches a max of nearly 5v (usually around 3-4v for a hall throttle).

If you get those results, the throttle is probably working as it should, and connected to the controller correctly (though the signal wire might not be, so you can trace that back to the controller itself and verify that the controller is reading that same voltage range as you turn the throttle on that signal wire).




If you explain to me, how to find and check the Hall sensors I'll make sure to check them as well.
First let's test the throttle, per above, and get the detailed info on how your bike is setup, such as where each wire goes, and what's on the end of it.

I highly recommend that you draw this all out for yourself (not just using whatever diagram is provided by the bike or controller manufacturer or seller, because your bike might not be wired correctly, which is why tracing it out is important) on a sheet of paper or signboard, carefully labelling each cable and wire, and matching those with notes on masking tape wrapped around each of those cables and wires on the bike itself, so you can easily use this to troubleshoot problems now and in the future. (you can also post it here in the thread and it will help us help you find which wires to test for which functions / problems as they come up).
 
Two thoughts occur to me:
1) Is there a circuit breaker disconnecting the battery from the controller that needs to be switched on? I spent an embarrassing amount of time thinking there was something wrong with my alibaba special before I noticed that it had two circuit breakers that I needed to switch on.

2) There's a relay located under the seat that checks for a 12 volt signal before allowing battery power to flow to the controller. On mine, the ground wire from that to the battery wasn't very well connected. Make sure yours is
 
Everything thus far is invaluable spot on. the fact that Amberwolf has stopped by is surely a blessing. Fletcher as well.

Brother, before these guys ICE you forever, ask them for their wiring diagram. you probably don't have one. If you don't get that, you might as well start creating it yourself, as amber wolf suggests. if your lucky, they will have followed some convention and all your grounds will be brown or green, your hot's = red, black, yellow, etc. Why? well, frequently they will change colors in the loom, they will use whatever they can find and then 6-12" to the end of the wire go from white dash-striped Pink, to the green/brown ground.

So if your throttle cables has anything but red/black. green/brown. blue/grey. ( the second colors being less common. Anything but those means you're in for a hell of a ride. the first thing you check is the voltage everywhere, 48v, 12v, 5v etc. now test the throttle. you might need to make a splice-jumper for the things that fail a lot, like the throttle itself. If it's a white molex connector or the fancy water proof automotive, getting a multimeter with long skinny probs is needed. jam those in the back of the connector for readings. If the connectors ( ebike ) are round, very small and waterproof, then, well, let me know and I can start explaining just how deep the rabbit hole goes. To test, the middle wire in the throttle is the variable output. easy to test. high failure rate.
The dash board not working is a serious issue, and you're going to want to check for power to it. ZERO power at the throttle and the dash? time to find the converter. on sit down scooters it has a tendency to be in the floor. If it is, check for a hole, if there isn't one, drill one to let the water out that will soon be filling up that pocket, as the Chinese rubber, or more correctly the "Chinese rubber like vinyl" will start to shrink/dry up/basically fail


Seriously, play nice and Get whatever they have for a schematic, offer to pay for it, if they refuse. I spent20-25 hours easily drawing out my 2008 Zapino
another polish friend of mine and the boards drew out his EVT4000e with easily 2x more cabling then the Zapino. It's done in pencil and it is precious.

Good luck and I'm sorry, you will likely never buy a bike from, china again, and I can't say I recommend it. There is a reason, they are so cheap.
 
Little things that you might have already done:
Regarding Bluetooth connecting: don't use your phone's Bluetooth settings to connect. Instead, go into the Fardriver app, hit the little Bluetooth symbol in the lower right corner, and tap "scan" at the top. The bike must be on to do this.
There may be a circuit breaker or two near the battery that needs to be turned on. It took me an embarrassingly long time to notice this on mine.
 
Well, he must have got it working, or rolled it off a cliff. Re-reading this, I should have emphasised bent pins. I've bent more than one pin, on the multi-pin controller cables, the more you pull them apart, the more likely the bent. Spring is coming!
 
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