Ebike Tailight Always On Help

[carlyai]

I have posted about this before, left it for a while, now back into it.

I have 2 Ebikes bought from China about 2 years ago and I assembled them here. 

Both bikes LED tail lights are always on, I think it's a fault and I am fairly sure the lights weren't on when I assembled them, but don't remember clearly.

I think it could be a controller fault, but with both bikes?

Also the on/off switch does not seem to do anything and the push button light stays on all the time.

The complete assembly is enclosed in an Al tube that slips into the frame and is a bugger to access but I have uncovered the top of the tube where the tailight, switch, charger connector and motor + connector are.

I have traced out some of the circuit (cct) which I have attached and also pictures of the light, connectors, on/off switch and wiring. I have not traced the wiring into the tube, battery setup and controller.

From the cct diagram it appears the LED light would be always on as voltage is present on the large purple and red wires coming up from the controller and batteries and the LED is across this feed. But this doesn't make sense to me. Why have the LED always on discharging the batteries and the push button on/off switch doesn't seem to do anything, always on.

I did post about this before and ordered a new switch, but twas the wrong type.

If you have any suggestions please let me know before my wife kills me for being possessed with this problem.The red and purple wires come up the tube from the controller and batteries I guess. They go to a connector on the frame where the motor cable plugs into. The tailight goes off to the right.

Voltage is always on the red and purple wires hence the LED light is always on.

The on/off push button switch light is always on.

There seems to be a bit of bodgie wiring with a 500 ohm resistor (R1) wired across the switch.

 

The head of the battery tube showing the LED, charger port and motor port. The push button switch rear is just visible.

 

 

Push button switch markings looked like 48v with C, NO, NC contacts but pushing button does nothing.

 

Push button switch, positive throw but always on.

[BritManToo]

If you have the three button controller.

Pressing and holding the top button usually switches the lights on and off.

[carlyai]

7 hours ago, BritManToo said:

If you have the three button controller.

Pressing and holding the top button usually switches the lights on and off.

The battery/controller tube is removed from the bike and the bike doesn't have a 3 way switch. 

I think (bad memory) pushing the on/off button turned on the tail light.

 

 

 

[Crossy]

11 hours ago, carlyai said:

Push button switch markings looked like 48v with C, NO, NC contacts but pushing button does nothing.

 

If you have +V on the C terminal then you should see +V on one of the others (NC/NO), flipping the switch should move +V to the other (NC/NO) terminal.

 

If it doesn't then the switch is dead (welded contacts?).

 

It should be easy enough to find another switch that will fit, but one of similar dimensions will likely fail in the same way (buy spares).

 

By the way, I avoid soldering on switches, the internals have an annoying habit of melting  

 

Get some crimp-on blade connectors, it's also easier to replace the switch when it fails.

[carlyai]

1 hour ago, Crossy said:

 

If you have +V on the C terminal then you should see +V on one of the others (NC/NO), flipping the switch should move +V to the other (NC/NO) terminal.

 

If it doesn't then the switch is dead (welded contacts?).

 

It should be easy enough to find another switch that will fit, but one of similar dimensions will likely fail in the same way (buy spares).

 

By the way, I avoid soldering on switches, the internals have an annoying habit of melting  

 

Get some crimp-on blade connectors, it's also easier to replace the switch when it fails.

Thanks Dave, good advice about the crimp on connectors too.

I've been looking up some wiring diagrams for Ebikes on YouTube and on one video have seen the 500 Ohm resistor but had a diode in series with it.

Might also have to investigate that further.

I have nearly discharged the battery as I thought I may need to get at the controller. If it (hopefully) is the switch I still may get into the controller/battery and see if there is a BMS that's OK.

Don't want to end up with something hot and throbbing between my legs. 🙂