E-TWOW Scooter only brakes when throttle pressed...

[thoomp]

Hey there,

Question for you all, as I really could use some electrical troubleshooting with a E-TWOW Booster S+ scooter, which I bought back in May.

After it sat for a few months unused (although correctly and periodically charged), now it won't accelerate when I turn it on. Complicating matters, when I tap the THROTTLE button, the front wheel actually brakes instead of accelerating -- and I can feel the front wheel lock up. Essentially, the throttle is incorrectly behaving just like a second brake button. The display comes on just fine, and there are no errors.

When I brought the scoot, it appeared to need a brand new battery. As the battery level would drop under throttle, I figured it was on its way out and I eventually ordered one (which took a long time to arrive. Recently replacing the battery didn't affect any of this behavior.

The only thing I can think of, is that something I may have disturbed soothing in the lower hinge area, as it wouldn't easily fold down. So I'm wondering if it has to do with a wire that's shorting out. As I didn't take apart anything near the display or buttons, I doubt it's from anything from the top of the scooter.

Other notes:

• When I first took it out of storage, I first noticed that the speedometer wasn't working when you roll the front wheel - and I don't believe the rear brake light powered on. For whatever reason, the speedometer now works and I'm noticing this braking behavior. Again, I want to "go" and not "stop."
• Again, replacing the battery didn't alter any of these symptoms.
• I can't find any wiring diagrams to troubleshoot.

As I'm very much used to wrenching on cars/motorcycles/Vespas - I figure this shouldn't be too difficult to troubleshoot. Per my logic, I figure it must have been something I did as it was working before I worked on it.

Finally, please be safe out there! At the time of this purchase, I wound up also buying a refurbished E-TWOW GT 2022 and I wiped out. I shattered my collarbone just two weeks after buying both scooters, and am still recovering from surgery many months later. I was probably going 20mph and likely hit a manhole cover; thankfully I was at least wearing a motorcycle helmet. (I'll be selling it here in Boston, if anyone is interested.)

Many thanks for your help!

 

[thoomp]

Okay - Here's a follow-up. I think there are two issues going on.

1) By going in and turning P1, P2, and P3 to OFF, that seemed to have worked (at least via my initial testing), which initially brought things back to life. I'm guessing maybe it had something to do with P3, which I think is cruise control. Figured I was home free, and would be simply be able to put everything back together.

2) In doing so, now we're back to square one. No response from the front wheel (no speedo, no braking). I'm guessing this second part has something to do with my opening everything up and there's a bad connection in there. I tried plugging/unplugging the connection to the motor multiple times, but no luck.

Clearly, the next step is to carefully disassemble everything again...and hopefully get it started again.

If anyone does have any schematics, that would be awesome. Thanks!

 

[amberwolf]

If it worked before whatever mechanical work was done on it, but not after, then it's likely something specifically to do with that work caused the problem either directly or indirectly.

WIres can break inside their insulation at bend points, and connectors can have contacts that pull just a little out of each other, or have wires that break at the back of the contact but still be held in by the insulation so you can't see the problem, and it may still make a little contact, but not enough.

If it was ever used in the wet or ridden thru puddles, etc, then water could have intruded into the motor, wiring, etc., and something could have corroded and be causing the problem.

If the motor(s) have wiring that comes out of an axle, it can be damaged by abrasions or impacts, and may not have any visible breaks but still be crushed inside. Or if the motor axle moutning hardware was insufficiently tight, it could have allowed the axle to rotate and twist the wries up; this usually has visible signs it has happened, and it too can damage wiring inside the cable housing.

 

[thoomp]

Thanks so much, @amberwolf -- I think we're on the same page here and I appreciate your suggestions. I disassembled/reassembling a few times per the lower area that I had gone through before -- and CAREFULLY wiggled wires and such until I was able to repeatedly get it to go on/off. I'm now pretty certain that the 5-wire "spring cable" that goes from the display/controller, all the way down the stem, and to the junction at the wheel is what is failing. I was able to wiggle that quite a bit with a lot of on/off...and eventually the display/controller now won't even turn on. So I'm guessing is that all my wiggling of that one spot caused that part of the wiring to completely fail (as now the controller can't even get power from the battery).

The funny thing is that all my assembling/disassembling itself (which I thought was where the culprit was), wasn't the break (or breaks in this case) in the line. However, the spring wire was genuinely borderline intact -- and my even attempting to get in there disturbed it indirectly (strain in a different direction) that caused it to fail.

Time to order a replacement wire and hopefully it'll be as right as rain!