Shorted the ignition barrel red & white cables & now dead. GROAN

[jkam]

Hi again,
Bummer.
I bought it with no barrel.
Sakura 207 blew fuses under rev increase.
Fixed it, (I was ecstatic)
I wanted to rush out & trial it but it was late & busy outside.
BUT, next day (while looking for missing barrel green lead connection) I briefly shorted the ignition barrel red cables to chassis & now dead.
I had substituted a 15A fuse wire in the battery fuse. which I have replaced. Still dead.
That was 2 weeks ago and the weather is preventing my investigating and so I ........live with the pain. lol

Controller damaged? (

Thanks

 

[Deleted member 4366]

Normally the live ignition wire is connected to the main battery wire inside the controller and the current doesn't go through any components so it can't damage anything, although it's possible that a track between the two on the controller's pcb has burnt.

First you should check with a voltmeter that you've got 40v on the controller's battery connector. Then check between your ignition wire and the battery negative whether it has battery voltage on it. If the controller has 40v, but nothing on the ignition wire, you could try making your own ignition wire by adding another wire from the battery +ve to the ignition switch.

 

[jkam]

Hi, Chrs D8, I am cured. I trust it's not just a panacea. I am now one happy (but cold) bunny. I will be out there, when the permafrost melts and the water table lowers, full of hope and armed with my trusty Fluke and your intel.
I can't locate a schematic. Are there a generic wiring diagrams that would assist?
Many Thanks

 

[jkam]

Hi again.
Unfortunately, I forgot to mention that the Euro plug read as a dead short on the 2 outer slots.
OC okay but SC is a worry.
I can't locate a schematic. Are there a generic wiring diagrams that would assist?

 

[jkam]

Correction.Black & red ignition wires arrive at top & side of battery kettle plug.
As there is a dead short between these it has to be a shorted controller & it seems to be the first 2 mosfets which I can't remove.

Here is a photo of controller

 

[amigafan2003]

One of these?

S207 Electric Power Bike Bicycle Electric Power Bike Bicycle scooter

 

[jkam]

YES, this one....... unfortunately

the same......been there- they don't deal with them anymore.

 

[Deleted member 4366]

Correction.Black & red ignition wires arrive at top & side of battery kettle plug.
As there is a dead short between these it has to be a shorted controller & it seems to be the first 2 mosfets which I can't remove.

Here is a photo of controller View attachment 5573

Doesn't sound right. What's your reasoning behind that? If there were a dead short, the fuse would blow every time you connect. It's normal to get a big spark when you connect.

 

[jkam]

Thanks but.....Am I missing something? - please elaborate.The IEC C14 plug shows 2ohms between red & black wires from battery which becomes O/C when controller disconnected. The 2ohms can be traced to two mosfets. 2ohms across the battery will blow the fuse.

 

[jkam]

Hi D8 I bow to your superior and empirical knowledge but we seem to have hit an impasse here or I have lost the plot.
Any further help would be really appreciated.

 

[Deleted member 4366]

I measured one of my controllers and got much higher resistance than that. Without exactly knowing what you did, it's difficult to say what's gone wrong, but the relation between the problem and cause should be logical. If there were a dead short in the controller, the battery fuse would blow. 2 ohms resistance would cause 20 amps to flow.

The ignition wire is connected to the battery, so when you short it out, the current doesn't go through anything in the controller that could do any damage. If you've got two open FETs, that would prevent your controller from working, but I can't see how shorting an ignition wire would do that, and I'd expect the resistance to be much lower than 2 amps.

You said that the first two FETs are open, but the first one (on left of your photo) is normally the regulator that supplies about 12v to open the FEt gates

 

[jkam]

Hi, "If you've got two open FETs, that would prevent your controller from working, but I can't see how shorting an ignition wire would do that, and I'd expect the resistance to be much lower than 2 amps. "
I think you need to revise that but thanks for responding.
I know the first device is a regulator (though I erroneously read a short there initially). The adjacent FETs read a dead short where they connect to the battery.

 

[jkam]

Seems like I have to go it alone nd will again attempt to remove a mosfet though I fear for the PCB.

 

[Deleted member 4366]

The FETs are connected directly to the battery, so you should expect a short on one side. The FET is like a gate. One side is connected to the battery but the gate is shut to the other side. The gate is opened when the controller CPU gives a pulse to a transistor, which then opens the gate for the same time as the pulse from the CPU. Here's a schematic:
http://www.avdweb.nl/Article_files/Solarbike/Motor-controller/China-BLDC-motor-controller-36V-250W.pdf

If you have 5v coming out of the 5v regulator (check red and black throttle) and approx 12v coming out the 12v regulator (Check between the black battery and each of the three legs), then your controller's probably OK, but if somehow battery voltage got onto a throttle or brake wires, you might have damaged the CPU.

I've read back through your posts, but I can't figure out what you're saying, so let's start from the beginning and do it logically:
First: Disconnect the battery from the controller. Have you got 36v on the two battery wires with the battery switched on?
Next: With the battery switched on, connect the battery connector/s to the controller. There should be a spark and a "snap" noise as you make the connection. Don't confuse this with a short circuit. It's only the capacitor/s charging up. If you do this test again straight away, you won't see sych a spark because the capacitor will be already full. It takes a while for it to drain down.

Report back when you've done these tests.

 

[jkam]

Hello again, Why no notification of replies via email on this forum? Did I miss an option? I gave up waiting for a reply but nevertheless, tx for new advice. Apologies if I confused you D8. I really appreciate your consideration in helping. Connecting the battery after the short blew a 20A fuse that worked OK before that. None of the other MFs read as a short. When a fuse blows then it's normally advisable to look for a fault rather than try again. I don't have an ammeter over 20A around. You are suggesting that the battery is connected to a short within the MF ......that opens when a V is applied to another terminal? Why doesn't the battery heat up? Too late & wet now to check anything tonight.
chrz

 

[Deleted member 4366]

I asked you to do a series of logical tests. If you don't give the answers to those, it's impossible to help you.