Can't get KT LCD5 headlight function to work

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kgff   100 mW

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Can't get KT LCD5 headlight function to work

Post by kgff » Sep 12 2019 6:55am

Hello,

this is my controller Image
https://www.aliexpress.com/item/32649376395.html
plus KT-LCD 5(which is virtually the same as lcd 3)

When holding the up button both lcd's backlight an ebike headlight are supposed to turn on,however only the lcd's backlight turns on
The voltage of the light pin in the light/speaker connector remains 0 instead of 48

What am I doing wrong?

Thank you

Jatem   100 mW

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Re: Can't get KT LCD5 headlight function to work

Post by Jatem » Sep 12 2019 2:49pm

Your controller has a plug for a mechanical light switch, and probably isn't using the display's light control. I mounted a small switch into the back of my light.

kgff   100 mW

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Re: Can't get KT LCD5 headlight function to work

Post by kgff » Sep 12 2019 3:09pm

Jatem wrote:
Sep 12 2019 2:49pm
Your controller has a plug for a mechanical light switch, and probably isn't using the display's light control. I mounted a small switch into the back of my light.
Why wouldn't a kt controller support a KT lcd? I don't get it, even the seller gave me a short list of KT lcd's I must have for this controller.. maybe there's a firmware update for it? or bad wiring.. or some wire from the LCD should connect to the lamp controller connector as I've seen with other installations
KT LCD5.PNG
KT LCD5.PNG (95.89 KiB) Viewed 1454 times

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Re: Can't get KT LCD5 headlight function to work

Post by Aquakitty » Sep 12 2019 4:27pm

Weird, are you my ebike doppleganger? I literally just came here for the same issue. I SWEAR when I first connected the lights, holding the "up" arrow turned them on. Then after that, I couldn't get it to work without using the switch on the actual headlight. From everything I am reading, the controller should support this, but maybe certain ones don't for some bizarre reason?

For the record I have the 12 mosfet KT48ZWSRLT-SJT02L

The only thing I changed on it in the settings afaik is the wheel size, pedal assist sensitivity and the max current.

Edit: I see your controller has a different issue. I have no trouble with the voltage, but with the control on the LCD working. Are you testing the wires with red and green for ground based on that chart?

What's the speaker wire for, some kind of horn control? The controller doesn't have a horn so I wonder what the point of that is, does the KT-LCD5 have a horn function?
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kgff   100 mW

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Re: Can't get KT LCD5 headlight function to work

Post by kgff » Sep 13 2019 1:14am

First of all just to clarify, I solved most issues that I reported in my previous thread (except throttle sensitivity, cruise function works only above 30 km/h)
Aquakitty wrote:
Sep 12 2019 4:27pm
Weird, are you my ebike doppleganger? I literally just came here for the same issue. I SWEAR when I first connected the lights, holding the "up" arrow turned them on. Then after that, I couldn't get it to work without using the switch on the actual headlight.that's good to know! From everything I am reading, the controller should support this, but maybe certain ones don't for some bizarre reason?
My lcd is v1.0(on the "lcd's" backside), so it's not a new kt lcd feature, however maybe lcd 3/5 were released to the market after my controller
For the record I have the 12 mosfet KT48ZWSRLT-SJT02L

The only thing I changed on it in the settings afaik is the wheel size, pedal assist sensitivity and the max current.
I will try to reset the controller and check again
Edit: I see your controller has a different issue. I have no trouble with the voltage, but with the control on the LCD working. Are you testing the wires with red and green for ground based on that chart?
I get normal voltage if I short the lamp switch(effectively using a lamp switch),so the 0 voltage is only without a lamp switch/lamp switch connector shorting
What's the speaker wire for, some kind of horn control? The controller doesn't have a horn so I wonder what the point of that is, does the KT-LCD5 have a horn function?
Yes I'm almost sure it's horn in chinese translation :D, many ebikes/escooters have horn features (just like my other escooter). the LCD's manual mentions no horn actuation fearture so the answer is probably not
I find the pswpower support abit unprofessional, they never give a clear response.. I just emailed kunteng "chn_1@163.com" about the issue, can you do the same? it may make them respond faster (if at all)
I found the mail here http://www.szktdz.com/en/news_show.php?article_id=415

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Re: Can't get KT LCD5 headlight function to work

Post by Aquakitty » Sep 13 2019 1:50am

I get normal voltage if I short the lamp switch(effectively using a lamp switch),so the 0 voltage is only without a lamp switch/lamp switch connector shorting
What do you mean by "shorting"?
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kgff   100 mW

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Re: Can't get KT LCD5 headlight function to work

Post by kgff » Sep 13 2019 2:41am

Aquakitty wrote:
Sep 13 2019 1:50am
I get normal voltage if I short the lamp switch(effectively using a lamp switch),so the 0 voltage is only without a lamp switch/lamp switch connector shorting
What do you mean by "shorting"?
nothing really important,instead of using a lamp handlebar on/off switch to test the controller's lamp output,I used a "short" by wiring the controller's lamp switch connector to itself.. you can consider it a permanent light switch ON, it was only temporarily diagnosis..

In other words, I simulated a lamp switch instead of connecting one

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Re: Can't get KT LCD5 headlight function to work

Post by Jatem » Sep 13 2019 3:06am

kgff wrote:
Sep 12 2019 3:09pm
Jatem wrote:
Sep 12 2019 2:49pm
Your controller has a plug for a mechanical light switch, and probably isn't using the display's light control. I mounted a small switch into the back of my light.
Why wouldn't a kt controller support a KT lcd? I don't get it, even the seller gave me a short list of KT lcd's I must have for this controller.. maybe there's a firmware update for it? or bad wiring.. or some wire from the LCD should connect to the lamp controller connector as I've seen with other installations

KT LCD5.PNG
The kt lcd works with the kt controllers, but not all functions are necessarily available in the controller depending on model and configuration.

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Re: Can't get KT LCD5 headlight function to work

Post by Aquakitty » Sep 13 2019 10:23am

kgff wrote:
Sep 13 2019 2:41am
Aquakitty wrote:
Sep 13 2019 1:50am
I get normal voltage if I short the lamp switch(effectively using a lamp switch),so the 0 voltage is only without a lamp switch/lamp switch connector shorting
What do you mean by "shorting"?
nothing really important,instead of using a lamp handlebar on/off switch to test the controller's lamp output,I used a "short" by wiring the controller's lamp switch connector to itself.. you can consider it a permanent light switch ON, it was only temporarily diagnosis..

In other words, I simulated a lamp switch instead of connecting one
I gotcha, I figured that. Anyway, just seems weird the LCD does not work with these controllers when they have the outs/connectors for them. I asked the seller I bought it from and they said it should work.

Mixing up the polarity of the lights wouldn't cause this, right? Because the signal is just from the LCD to the controller and nothing to do with the lights themselves.

Not having the lights turn off with display is the only reason I care, because we tend to forget to turn things off around here. This weekend I'll experiment with it a bit.
Rans Enduro Sport w/Sturmey-Archer XFRD8, TSDZ2 open source mod 48v
GT Verb Comp f/s TSDZ2 open source 48v
Diadora Ampio bargain f/s TSDZ2 48v
2020 Diamant 247 belt drive 1000w 9C 48v
Hardtail made from random bits I had laying around, ginormous old Marzocchi fork, BBS02

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E-HP   100 kW

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Can't get KT LCD5 headlight function to work

Post by E-HP » Sep 13 2019 10:57am

Aquakitty wrote:
I gotcha, I figured that. Anyway, just seems weird the LCD does not work with these controllers when they have the outs/connectors for them. I asked the seller I bought it from and they said it should work.

Mixing up the polarity of the lights wouldn't cause this, right? Because the signal is just from the LCD to the controller and nothing to do with the lights themselves.

Not having the lights turn off with display is the only reason I care, because we tend to forget to turn things off around here. This weekend I'll experiment with it a bit.
The other controller is set up to use an external switch. Not all KT controllers have all features, but the displays are used for many models (for example, you wouldn’t automatically get regen with a display that has those options, unless the controller supports it).

Polarity makes a difference if you’re using LED lights, because of the circuitry (buck converter) that drives the LEDs.

I had the same fear about not remembering to shut off my headlight, but mine is so bright, it’s hard not to notice it on. I’ll eventually wire up a switch panel with indicator light, unless I get ambitious and wire in a relay to control the whole lighting and 12v subsystem when the controller is turned on.


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Re: Can't get KT LCD5 headlight function to work

Post by Aquakitty » Sep 13 2019 12:56pm

E-HP wrote:
Sep 13 2019 10:57am
Aquakitty wrote:
I gotcha, I figured that. Anyway, just seems weird the LCD does not work with these controllers when they have the outs/connectors for them. I asked the seller I bought it from and they said it should work.

Mixing up the polarity of the lights wouldn't cause this, right? Because the signal is just from the LCD to the controller and nothing to do with the lights themselves.

Not having the lights turn off with display is the only reason I care, because we tend to forget to turn things off around here. This weekend I'll experiment with it a bit.
The other controller is set up to use an external switch. Not all KT controllers have all features, but the displays are used for many models (for example, you wouldn’t automatically get regen with a display that has those options, unless the controller supports it).

Polarity makes a difference if you’re using LED lights, because of the circuitry (buck converter) that drives the LEDs.

I had the same fear about not remembering to shut off my headlight, but mine is so bright, it’s hard not to notice it on. I’ll eventually wire up a switch panel with indicator light, unless I get ambitious and wire in a relay to control the whole lighting and 12v subsystem when the controller is turned on.


Sent from my iPhone using Tapatalk
I know the polarity matters with LED lights but I think the light has some kind of protection because reversing it made no difference. One of my light cables wasn't labelled, and only had the white line, which could be 50/50, but don't see how that would affect the controller.
Oh BTW I found on another sellers listing my controller, and it says "Support 36V or 48V Light Control". I assume that means this should be working so I will have to get to the bottom of this.
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Re: Can't get KT LCD5 headlight function to work

Post by amberwolf » Sep 14 2019 12:37am

I don't know if this is applicable to *this* LCD, but IIRC, one of the various other threads about LCD light functions vs external headlights/etc. mentions that the little electronic switch (FET) inside the LCD that does the switching is very low power, and is meant to just "tell" the light to turn on, not to actually carry the current for the light.

It could be damaged by doing that (or by shorting it), so that might be why it isn't working.

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Re: Can't get KT LCD5 headlight function to work

Post by AHicks » Sep 14 2019 8:28am

amberwolf wrote:
Sep 14 2019 12:37am
I don't know if this is applicable to *this* LCD, but IIRC, one of the various other threads about LCD light functions vs external headlights/etc. mentions that the little electronic switch (FET) inside the LCD that does the switching is very low power, and is meant to just "tell" the light to turn on, not to actually carry the current for the light.

It could be damaged by doing that (or by shorting it), so that might be why it isn't working.
Regarding the KT based controllers, I believe that's true. The controller circuitry is not going to support much draw. For the LCD switched headlight, the instructions I have with one of mine mentions "max current 100mA, max power 5W otherwise will be burnt".

They do provide a second headlight lead, that's designed to supply "2A current, 100W light", but you must install your own switch. The LCD has nothing to do with it.

There's a chance that our OP may have already burnt out that circuit by exceeding their specs, and also a chance this controller wasn't equipped for the LCD switched circuit. Not all of them are.

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Re: Can't get KT LCD5 headlight function to work

Post by kgff » Sep 14 2019 9:48am

AHicks wrote:
Sep 14 2019 8:28am
amberwolf wrote:
Sep 14 2019 12:37am
I don't know if this is applicable to *this* LCD, but IIRC, one of the various other threads about LCD light functions vs external headlights/etc. mentions that the little electronic switch (FET) inside the LCD that does the switching is very low power, and is meant to just "tell" the light to turn on, not to actually carry the current for the light.

It could be damaged by doing that (or by shorting it), so that might be why it isn't working.
Regarding the KT based controllers, I believe that's true. The controller circuitry is not going to support much draw. For the LCD switched headlight, the instructions I have with one of mine mentions "max current 100mA, max power 5W otherwise will be burnt".

They do provide a second headlight lead, that's designed to supply "2A current, 100W light", but you must install your own switch. The LCD has nothing to do with it.

There's a chance that our OP may have already burnt out that circuit by exceeding their specs, and also a chance this controller wasn't equipped for the LCD switched circuit. Not all of them are.
I only shorted the controller's light switch connector which is completely safe,has nothing to do with the lcd, nothing was burned
I actually have a light switch which i just installed successfully, I just wanted to have another switch my for my 9 led elements (3 strips, 2 rear, 2 front, 1 rear brake, 1 headlight), because I didn't want them always to turn on together..

Does anyone know how can I set the rear light/lights to "blink" when braking, is there a kt controller feature for it?

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Re: Can't get KT LCD5 headlight function to work

Post by Aquakitty » Sep 14 2019 12:56pm

amberwolf wrote:
Sep 14 2019 12:37am
I don't know if this is applicable to *this* LCD, but IIRC, one of the various other threads about LCD light functions vs external headlights/etc. mentions that the little electronic switch (FET) inside the LCD that does the switching is very low power, and is meant to just "tell" the light to turn on, not to actually carry the current for the light.

It could be damaged by doing that (or by shorting it), so that might be why it isn't working.
Hmm ok thanks. I think in my case it just doesn't have the capability. I did more looking this morning and came across this:
"The front light voltage is the same as the controller (36V or 48V), could not be controlled by the display".
So I guess that just means it's a direct power out only and my imagination turned it on and off :lol:
But, the place with this info didn't have my exact controller, just other ZWS versions. If only KunTeng had actual information on their website.
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Re: Can't get KT LCD5 headlight function to work

Post by AHicks » Sep 14 2019 7:15pm

That's been my experience as well. I've bought controllers that were supposed to have cruise but did not, supposed to have regen and did not, and unfortunately there's little you can do. The seller accuses the buyer of incompetence, and offers to "test" the controller for you when you insist on the controller performing as advertised. The freight to return the controller makes that cost prohibitive, plus the fact the seller then has your controller AND your money. You're at his mercy at that point!

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Re: Can't get KT LCD5 headlight function to work

Post by Diva » Sep 24 2019 2:13pm

On the last KT controller I've had in my hands, the light switching module that feed a light directly by the controller is absent. The only thing that is proposed (just by pswpower) is a light and horn fed by your battery trough a switch

the light: http://www.pswpower.com/ven.php?cargo.2016-38-4x8c
the switch: http://www.pswpower.com/ven.php?cargo.2016-38-4x7r

I'd like to find another option too...

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Re: Can't get KT LCD5 headlight function to work

Post by egul » Feb 23 2020 8:43am

I've just gone through some old posts so didn't notice yours until now.

I discovered that the motor controller itself has a connector inside, which has 5v on it when the light is switched on. If you're OK with some electronics you could wire up a FET transistor or similar which could switch the lights on, as you can't connect the light directly to this connector as it won't supply enough current.

I posted the details of the connections here - maybe this will help you.

viewtopic.php?t=100898

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Re: Can't get KT LCD5 headlight function to work

Post by kgff » Mar 14 2020 1:21am

egul wrote:
Feb 23 2020 8:43am
I've just gone through some old posts so didn't notice yours until now.

I discovered that the motor controller itself has a connector inside, which has 5v on it when the light is switched on. If you're OK with some electronics you could wire up a FET transistor or similar which could switch the lights on, as you can't connect the light directly to this connector as it won't supply enough current.

I posted the details of the connections here - maybe this will help you.

viewtopic.php?t=100898
Thanks! I'll see what I can do and report back probably within 2 weeks :bigthumb:

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