Strange problems with KT controllers and diplays?

[Promille]

Hi, i have a very strange problem. I converted my dads bike like a year ago with a front wheel kit that has a kt controller and a kt lcd1 and waterprof higo harness and wp 9pin motor cable , and the problem with this kit was that it never showed speed and battery indication just on/of pedal assist and throttle works.

Anyway my dad was happy about the bike and did not care but it anoyed me so i orderd three kt controller kits with differnt lcd’s from China and when i finally got them i tested them all on a mxus xf07 motor and everything worked as it should on all of them.

So i took one of the new controllers and tried it on my dads bike first with the existing wiring and lcd but no still the same problem, ok so i tought maybe it was something with the wiring and tested al new wires for both motor and controls, still the same problem so i tested one of the new lcd’s in this case a lcd4 nope still same problem??.
Then i put all the old gear back on my dads bike and forgott about since it didn't bother him anyway.

But now a couple of days ago a friend wanted to buy my mxus xf07 motor as a kit so ok no problem it worked great before ,i connected everyting and boom same problem as on my dads bike? but the strangest thing it's the same with all three controllers and displays now maybee beacuse i have been switching everything around when testing , display, controller, wiring and so on.

I have even tried conecting everything to a dd hub motor i have laying around to rule out that it could be something with the mxus motor, but no same probem.

I know there is software protocol in both the controller and display maybee that has been corupted somehow by the faulty controller or display when i have been swapping everything around in my frenzy testing to get the damn things to work properly.

Has anyone here had a similar problem with kunteng devices ??

 

[E-HP]

i tested them all on a mxus xf07 motor and everything worked as it should on all of them.


But now a couple of days ago a friend wanted to buy my mxus xf07 motor as a kit so ok no problem it worked great before ,i connected everyting and boom same problem as on my dads bike? but the strangest thing it's the same with all three controllers and displays now maybee beacuse i have been switching everything around when testing , display, controller, wiring and so on.

Any reason you didn't replace both the controller and display the first time, since you didn't know which component was defective?

Maybe you assumed that the original controller was the problem, when it was the original display, and hooking the bad display up to the new controller fried it. Then swapping thing around ensure that everything got fried?

 

[AHicks]

If the speed isn't working, at least while under power, my bet is there is a parameter set incorrectly. Have you tried doing a reset to default settings and starting over again?

 

[Promille]

i tested them all on a mxus xf07 motor and everything worked as it should on all of them.


But now a couple of days ago a friend wanted to buy my mxus xf07 motor as a kit so ok no problem it worked great before ,i connected everyting and boom same problem as on my dads bike? but the strangest thing it's the same with all three controllers and displays now maybee beacuse i have been switching everything around when testing , display, controller, wiring and so on.

Any reason you didn't replace both the controller and display the first time, since you didn't know which component was defective?

Maybe you assumed that the original controller was the problem, when it was the original display, and hooking the bad display up to the new controller fried it. Then swapping thing around ensure that everything got fried?

Yes i assumed that the controller was defective beacuse i had actually tried a kt 880 led from another bike first before ordering everything and the 880 led did just flash low batt but worked as it should when put it back on it's original bike.

 

[Promille]

If the speed isn't working, at least while under power, my bet is there is a parameter set incorrectly. Have you tried doing a reset to default settings and starting over again?

Actually the display does not show anything it's blank only pas works. But i have not tried reseting maybe that will do the trick.

 

[Promille]

If the speed isn't working, at least while under power, my bet is there is a parameter set incorrectly. Have you tried doing a reset to default settings and starting over again?

Actually the display does not show anything it's blank only pas works. But i have not tried reseting maybe that will do the trick.

This is what i mean with blank,

 

[d8veh]

There are 5 wires in the cable:
Red battery voltage
Black ground
Blue battery voltage only when the LCD is switched on
Green and White Tx and Rx comms

The LCD will work as long as it's connected to the red and black wires in the harness. It works completely independently from the rest of the bike like that, but it can't do anything other than light up and show the PAS levels going up and down.

If the blue wire is also connected, that wire powers the controller, so the throttle will work the motor and you get the default PAS level 1, so that brings the question: Are all PAS levels working? If not, you have a problem with the comms. If yes, it's a speed sensor problem or a speed sensor setting.

Does your dad's bike have a speed sensor, and is it working? You can check it with a meter if you're lucky. Waterproof connectors don't allow you to get your probes on, but if you open the controller and it's not potted, you can probe where the white wire from the motor is soldered. You should be able to see it pulsing on and off with 5v when you turn the wheel. Some motors don't have the internal sensor, so you have to fit a wheel magnet one. Too often,the magnet comes unstuck in motors that do have the sensor, in which case the sensor doesn't work.

When anything stops the comms from working, you get a display like you showed, and I think you get the same when the CPU gets damaged by a wrong connection. If you let the battery pin touch one of the comms pins, the CPU gets wiped out. That also happens when water gets in the LCD or when the wires aren't soldered properly.

One final point. When those 1 into 4 harnesses first came out, I know someone that had a whole batch of bikes with faulty ones, where after some time, a short came where the harness branched. It wiped out both the LCD and the controller. We lost no end of controllers and LCDs before we figured what the problem was, and so did all the dealers, who did the same as you and me - try parts off other bikes to see which part was faulty. The problem was that every part became faulty. After we figured out what the problem was, we knew that if somebody got the LCD not displaying properly, we had to replace the controller, LCD and the harness.

The last time I saw the problem you described was because the cable had been pulled and the white comms wire had broken off.

Considering everything, it wouldn't surprise me if you had a short to one of your comms wires at the LCD end because that would wipe out the comms in any controller you connected. The short would have to be to the red or blue wire. I would open the LCD and check where the wires are soldered.