TSDZ2(B) no longer disables from brake sensors

[Watchamacallit]

Hi all

So i ride my TSDZ2B with brake sensors, and, having verified with a multimeter (and even a hub motor) That the brake sensor/cutoffs work 100% perfectly fine, my TSDZ2 seemingly prefers to just ignore the sensor inputs - where'as in the past, they previously worked fine.

i operate my TSDz2b with a throttle, so i prefer to have them as an extra insurance measure in case of any sort of malfunction or runaway. I also use Open Source Firmware on it, with, of course, throttle and brake sensors checked (it's not been altered or upgraded recently to warrant suddenly not detecting the brake sensors).

has anyone else encountered this before? The sensors i use are literally mechanical switches, embedded into the brake handles (not magnets). Very simple and, as i said, operate perfectly fine when measured with a multimeter or connected to another motor; just the TSDZ2B seems to have an issue with it.

Cant help but wonder if there's some sort of circuit thats burnt out, perhaps in the controller, or the LCD screen (I use a VLCD5 display).

If any one can offer any input it would be appreciated.

 

[docw009]

Did you recently pull the connectors off? The VLDC5 display really has stiff connectors. You got to push hard to seat them. I've had the throttle not work because of that on two different bikes and this was after running for months. They just worked loose. Brake connectors are just as stubborn.

 

[E-HP]

Brake cutoff circuits usually have a pull-up resistor on the signal line so the voltage from the TSDZ2 brake connector should be around 4v. If the brake lever works elsewhere, then the issue could be on the controller side. I’d check for voltage on the connector while the controller is on.

 

[Watchamacallit]

Did you recently pull the connectors off? The VLDC5 display really has stiff connectors. You got to push hard to seat them. I've had the throttle not work because of that on two different bikes and this was after running for months. They just worked loose. Brake connectors are just as stubborn.

No it's definitely seated fully. In fact i made/repaired the connectors myself in the past (I'm fairly handy with a multimeter/soldering)

Brake cutoff circuits usually have a pull-up resistor on the signal line so the voltage from the TSDZ2 brake connector should be around 4v. If the brake lever works elsewhere, then the issue could be on the controller side. I’d check for voltage on the connector while the controller is on.

Thanks alot for this. Just to clarify:
If i Use my multimeter to measure the voltage between the brake sensor connector's signal pin and ground pin,if no brake is applied, I should see around 4 volts is that right?, If I apply the brake, the voltage should drop to 0 volts?

In this case, if we assume the 4v remains present even with brake on, does this indicate a faulty controller, and, if so, could someone such as myself (Who has access to other failed controllers) potentially repair the damaged component(s) on the PCB withoout having to outright buy a replacement?

 

[E-HP]

If i Use my multimeter to measure the voltage between the brake sensor connector's signal pin and ground pin,if no brake is applied, I should see around 4 volts is that right?, If I apply the brake, the voltage should drop to 0 volts?

Yes, you are describing what should happen.

In this case, if we assume the 4v remains present even with brake on, does this indicate a faulty controller

This shouldn’t occur, unless you have an intermittent ground between the connector and controller (again, assuming your brake cutoffs are good). I’d disconnect the battery and display, and check the continuity between the battery(-) input to the controller and the ground pin of the controller’s display connector, with an ohm meter.

 

[Watchamacallit]

Yes, you are describing what should happen.

This shouldn’t occur, unless you have an intermittent ground between the connector and controller (again, assuming your brake cutoffs are good). I’d disconnect the battery and display, and check the continuity between the battery(-) input to the controller and the ground pin of the controller’s display connector, with an ohm meter.

ok, great, thanks again.

So upon measuring, i've observed that the 4v is constantly present. In addition to this, upon pulling a brake lever, it actually creeps up to 4.5-5v, then on release, goes back down to 4v.

 

[E-HP]

You shouldn’t see volts when using the resistance/ohm setting. Plus, if the battery is disconnected, there shouldn’t be voltage, especially on the ground conductors. Is you meter working? Are the batteries in your meter dying?

 

[Watchamacallit]

You shouldn’t see volts when using the resistance/ohm setting. Plus, if the battery is disconnected, there shouldn’t be voltage, especially on the ground conductors. Is you meter working? Are the batteries in your meter dying?

I actually think i've found the issue.

I think the wiring is bridging inside the insulation just before it reaches the brake switch, because if i move the wire in a very specific place, it behaves normally. This might also explain why it seemingly worked fine on another motor/under continuity, my guess is in both instances i had the cabling just right where it wasn't shorting.

I'm going to try new wiring and see if that solves the problem.

 

[E-HP]

It’s likely a poor/damaged ground conductor.