5th Wheel EB17 ebike with non working headlight?

[DoxRemux]

Hi, two months ago I purchased a brand new 5th wheel EB17 ebike on amazon, I did the assembling which was very easy, all wires/plugs came correctly connected, but I found that the headlight with horn will not work, I spent some time checking the plug connection, but nothing, it was properly connected and still got nothing, no light, no horn when pushing the buttons, I used a volt meter and saw that I have 38 volts on the connection plug, I found the problem! I have a faulty headlight! I thought...

I asked twice the seller for a new headlight but got no answer, after two weeks I bought a new cheap headlight with horn that works on 12 to 60 volts, and I found that it does not work either, I doubled checked everything, I saw how the new headlight works good connected to a 12v power supply that I have, so it really works, the problem is the ebike, it seems that I have 38 volts on the headlight plug but it delivers very low current because some problem in the ebike mainboard/circuit board.

Its been almost two months since the purchase, and I don't have the box anymore, I don't think I qualify for a return, does anyone know if the bike might have a blown fuse or a burnt mosfet that controls the headlight with horn? Thanks.

 

[Annieolnie]

Manuals+ has your manual. You have a 36v system, having 38v at the plug should be fine. I'm guessing because you have separate horn and light switch, that is where the problem lies. Is there a way to open that up and check your connections? I'll post the picture from their page. By the way, I didn't know that the Chinese translation for horn would be megaphone.

 

[DoxRemux]

Manuals+ has your manual. You have a 36v system, having 38v at the plug should be fine. I'm guessing because you have separate horn and light switch, that is where the problem lies. Is there a way to open that up and check your connections? I'll post the picture from their page. By the way, I didn't know that the Chinese translation for horn would be megaphone.

Thanks, that picture of the display is very different from mine, my EB17 has a different display model, mine does not show anything about light or horn, just very basic info, and next to the display on the left I have two physic buttons, one for light and one for horn, I see 38v on the plug when light button is on, and the same when pushing the horn button, it seems like for protection that headlight plug is not directly connected to the power source, somewhere there should be a circuit with mosfet that driver these two components, here is where I might have a problem, using a multimeter the line shows the correct voltage, but the current is abnormally low due to a fault.

Because this seems to be a very big problem and I cant do anything more, I will simply ignore it, I think I clearly have a factory problem, I had bad luck but at least its not something serious, just the light and horn, then my anger is much less . Thanks.

 

[DoxRemux]

Manuals+ has your manual. You have a 36v system, having 38v at the plug should be fine. I'm guessing because you have separate horn and light switch, that is where the problem lies. Is there a way to open that up and check your connections? I'll post the picture from their page. By the way, I didn't know that the Chinese translation for horn would be megaphone.

Do you think that taking apart that part that has the two switches might reveal something wrong? so inside that part might be more than the two switches? at least I can say that the two switches seemed very normal, responsive and good to me when I was pushing them to make the test with the multi meter, but I don't know.

 

[Annieolnie]

Do you think that taking apart that part that has the two switches might reveal something wrong? so inside that part might be more than the two switches? at least I can say that the two switches seemed very normal, responsive and good to me when I was pushing them to make the test with the multi meter, but I don't know.

OK, well obviously Manuals+ doesn't have your manual. You do have separate switches, though. If you unwind the coil wrap does it lead to a separate julet plug, if so that would give you a test point. Since the problem is so isolated, I am very suspicious of that separate switch.

 

[Annieolnie]

Could you give me a better picture of that switch? It turns out a number if independent switches like that are available. If it has a julet plug, you could have a bent pin and this could be simple.

 

[DoxRemux]

Could you give me a better picture of that switch? It turns out a number if independent switches like that are available. If it has a julet plug, you could have a bent pin and this could be simple.

Oh ok, here are few more pics. Thanks.

This is the female plug where headlight connects.

 

[DoxRemux]

Do you also want to see if the buttons module has a plug where it could have a bended pin? headlight plug has 4 pins, but one is not used, with the tester I checked that I have GND and light and horn positive, 3 wires.

 

[Annieolnie]

The female plug you are showing, is that on the button connection side or the controller side? Do you have power at the side coming from the bike? A lot of people sell this switch, but they don't say which julet plug comes on it. You can easily get it with loose wires and add a julet plug. It also comes in a yellow 3 pin. But first you need to see if you have continuity on the bike side. How much voltage is coming to it and how do the pins look? I find it odd that one pin is not used. If you jump it, does your horn work?

 

[DoxRemux]

The female plug you are showing, is that on the button connection side or the controller side? Do you have power at the side coming from the bike? A lot of people sell this switch, but they don't say which julet plug comes on it. You can easily get it with loose wires and add a julet plug. It also comes in a yellow 3 pin. But first you need to see if you have continuity on the bike side. How much voltage is coming to it and how do the pins look? I find it odd that one pin is not used. If you jump it, does your horn work?

I still don't know where all cables come from, I need to uncoil the cables to see their path, I only checked with the volt meter the female plug where headlight connects.

I find it odd that one pin is not used. If you jump it, does your horn work?

It makes sense to me because when I took apart the headlight I saw the 3 cables needed in order to power light and horn, gnd, light + and horn +, both use the same gnd line, see this picture of the headlight circuit board, let's say that I took my voltage readings with the multi meter from these 3 cables, I double checked the connections of the new headlight that I mentioned before, which was also tested using a 12v power supply that I have, making sure that it is working isolated from ebike. I feel very pessimistic about solving this, ChatGPT told me that maybe the electronic circuit that drives light and horn could have a faulty electronic component like a blown mosfet or something, so I got 38 volts but that's a ghost voltage that can't power my headlight.

 

[Annieolnie]

So, step back a bit. You did not say, but I'm guessing the plug on the bike side is female, ( it can be either on different bikes). If you use sewing needles, T pins or even staples and you jump the plug on the bike do you have lights or horn? Also, you have a 36v system, 36v is what you are running. It is not a ghost. It certainly can power your headlight and don't get me started on AI. It is creating a stew from everything it distills on the internet, probably including motorcycles, atvs and a Rhumba that has a light on it. Start by seeing if the horn goes off when you go around the switch.

 

[DoxRemux]

Yes, the plug of headlight is male and it connects to a 4 pin female plug (I posted the pic of the female plug where headlight should connect).

My first step was using sewing needles on that female plug to connect the multi meter terminals and get a read, I saw 38 volts which is ok for a 36v battery, then I did not use the sewing needles anymore, I unsoldered the headlights circuit board to use the headlight cable with its 3 wires, and I measured voltage again from there, saw 38v again, so cable looked good to me and I used it to connect the new headlight there, this new headlight works with 12 to 60 V, but it did not work on the ebike, I checked connections several times for mistakes but everything was correct, I thought that the new headlight was faulty too, so I also connected it to a 12v power supply and it worked good.

Do you think that I should use the sewing needles again to connect the new headlight there without using the original cable which could be bad? at least I saw it was throwing 38 volts when I used it. Thanks.

Forgot to say that the new headlight had a different plug, so using the original cable with plug was necessary, it also has 3 wires, gnd, light and horn, I did not open the new headlight, I did temporal connections using its wires, checked everything few times, and finally even reversed polarity but nothing.

 

[Victor Dupont]

My understanding of @Annieolnie's very smart suggestion, is to use needles to short-circuit the button. Basically getting into a situation where the light and horn are directly connected to the cables going INTO the switch. If they honk and light up continually in such a setting, it would mean the problem lies within the switch. If they don't, the problem is upstream.

 

[DoxRemux]

My understanding of @Annieolnie's very smart suggestion, is to use needles to short-circuit the button. Basically getting into a situation where the light and horn are directly connected to the cables going INTO the switch. If they honk and light up continually in such a setting, it would mean the problem lies within the switch. If they don't, the problem is upstream.

Oh I can see it now, sorry to Annieolnie, I was not understanding it but its clear now, I will give a try to that untried yet operation, thanks to both of you.

 

[DoxRemux]

Please one more question, when working on the buttons plug should I have special care with what I short circuit? Can I simply short circuit all it's pins togetter without blowing anything? Doing that will only activate the light and horn at the same time, just like having both buttons on, right? Thanks.

 

[Victor Dupont]

I'm pretty sure you SHOULD NOT short everything together. The plus and the minus should not touch each other. My understanding is that the plus going into the switch should be shorted to the plus going toward the light and the horn, and the minus going into the switch should be shorted to the minus going toward the light and the horn.

If you short the plus and the minus you're likely to burn your controller, maybe even your battery.

Let us know if it's unclear

 

[Annieolnie]

You only need two pins.You are simply going around what the switch does. You aren't really shorting anything, but creating a jumper. Another test that you might feel more comfortable with, which takes the battery out of it all together, is to set your multimeter for continuity and working on just the switch side, connect your leads to two of the male pins on the plug and work the switch. If the switch is making a circuit at any time, as you play with it, you should get a beep. This won't preclude a bent pin but it will tell you if something in the switch is not connected. This test is just on the switch side, do not connect it to the bike side plug. See what happens.

 

[DoxRemux]

Ok I see, I understood that I first should work on the isolated buttons module to identify the pins that close the circuit, and also see how it works when testing its continuity, now that I am familiar with its pins, I can work on the plug where buttons module connects, maybe a female plug that I will jump it with the needles and see what happens. Thanks, I will do that tomorrow and see what happens, I will post soon.

 

[DoxRemux]

I already jumped the button module, it confirms that button module works good and that I have the expected voltage 38V, but with a very low current, so both headlight and horn can't turn on, I actually just realized that there's some light in the headlight, a very very low beam, barely noticeable, it's the first time I took a look at it in a dark room, that's why I did not notice it before when I was outdoor, it works the same in both ways, when jumped with needles and with button module connected, some light and horn electronic driver may be bad, so it's not throwing enough current. Horn does not make any sound. Battery is 100% charged. I did not find any other problem when riding the bike, it rides pretty good, reaching 22 mph, which is its max speed, 36V350W.

It was very easy to find what pins to jump using the continuity tester, buttons plug has 3 pins only. Thanks, I had bad luck with this , at least everything else works well .

 

[Annieolnie]

Well, you are doing a good job and I stand corrected. You may have been right from the beginning. You could have a bad connection or blown mosfet in the controller, which is suppose to send current to the headlight. Your bike should be under warranty. Do you want to tell the company you have no lights and horn and that you know it is not the switch and see if they will send you a new controller?