Help with IZIP Ezgo folding bike please.

[D-I-Y 82]

New to e.bikes, bought this Izip Ezgo some time ago. Trying to get it going!
Came without batteries or box so I am using 2X 12v car batteries in series to test it mounted on rear carrier.
First test on road no action at all.
Now in shed with back wheel raised.
The only way I can get any action is as follows.
1.Open up throttle twistgrip , then
2.Connect battery. ie. touch pos. supply lead to battery plus.
Sometimes the wheel turns , other times there is a whirring from the motor but wheel doesn,t turn. sometimes nothing ,but turning the wheel backwards a bit and reconnecting power , and it may run.
Once running, turning the pedals slowly and wheel speed increases as I understand it should?
I can't start the motor by pedalling the machine with the battery connected whatever I do with the throttle.
Don't know how old it is but controller (Ananda) is dated 2006.
No obvious damage anywhere. Some of the colour coding in the 'electrics box ' seems a bit off but can't
find an exact wiring diagram.
Any help, comments, ideas gratefully accepted. Thanks!

 

[amberwolf]

I don't think it is applicable, but this is the only thread specifcally on that bike I found
https://endless-sphere.com/forums/viewtopic.php?f=2&t=72040&p=1087590

I don't know how that one is designed to operate, but it sounds like perhaps it does have motor hall sensor (or wiring/connector) issues (which is what the above thread found).

 

[D-I-Y 82]

Thanks for the reply. I had seen that thread but can't find any bad connectors etc. as OP did . I am going to look into Hall sensors and motor supply as described by 'Jeremy' in thread ' troubleshooting an e bike 'on p.210. Thanks again.

 

[D-I-Y 82]

So testing with analogue meter.
Motor supply.
Yellow-Green. Green-Blue .Blue -Yellow all show no measurable resistance. Yellow.Blue.Green to motor case, all give infinite resistance.

Sensor wires at connector.
Red-Black 5v.
Yellow to Black and turn wheel 0-5v
Green to Black and turn wheel 0-5v
Blue to Black and turn wheel ZERO V!!

Disconnect controller and test resistance between supply wires at controller. Yellow-Green. Green -Blue .Blue - Yellow. All show infinite resistance.

So seems we have a fault on blue sensor or its wiring. Do you think I can assume tne fault is in the motor /wiring or could it be a controller fault. Any test to decide which?.

Currie hub motor. Connectors at bottom bracket. Motor seems quite 'healthy" once started as above.

 

[amberwolf]

So testing with analogue meter.
Motor supply.
Yellow-Green. Green-Blue .Blue -Yellow all show no measurable resistance.

Assuming you are talking about the hall sensor signal lines, that means they're all shorted to the 5v line, if that's what you mean by "motor supply". That's a problem, as there should be very high or infinite resistance from signal to 5v or ground, when the hall is not powered and not "on".

If you mean there's no resistance between each pair of signals, then that means they're shorted to each other, which is also a problem.

They should be very low resistance to ground when the hall is powered and on, if the signal wire is connected to nothing else but the meter.

Can't safely do a resistance test from 5v to signal when the hall is powered up.

If by "motor supply" you mean the phase wires, then those should all show shorted to each other because they are connected directly together within the motor itself.

Yellow.Blue.Green to motor case, all give infinite resistance.

That's good, as it means they're not shorted to the axle or stator.

Sensor wires at connector.
Red-Black 5v.
Yellow to Black and turn wheel 0-5v
Green to Black and turn wheel 0-5v
Blue to Black and turn wheel ZERO V!!

If that is with the controller connected to the motor, and powered on, then the internal controller pullups should make the blue signal 5v. If it doesn't, then either
-- there is no connection from the test point to the controller (and the sensor)
-- or the test point is shorted to ground somewhere along it's length (anywhere from inside the controller to inside the motor at the hall sensor itself).

All the hall sensors do is ground the signal line whenever they detect a magnet. So the voltage doesn't come from the hall itself, it comes from the controller side, in the common design of these systems.

If you are testing with controller and motor disconnected, then the hall signals may not be valid, because there is no pullup, so you may not get a 5v signal when the hall is not on (not grounded), and it may "stick" at 0v, becuase the sensors don't output a voltage, they just ground the voltage from the controller's internal pullup resistors on the signal lines.

Disconnect controller and test resistance between supply wires at controller. Yellow-Green. Green -Blue .Blue - Yellow. All show infinite resistance.

Assuming you mean the hall sensor signal wires, then if that is with power and motor disconnected from controller, and measuring from 5v to each signal on the controller side of the wires, then you should get something like 5kohm to 10kohm, from the internal controller pullups (resistors on each signal wire to 5v). If you don't get that on any of them, something is wrong with all of them, or with how the measurement is being made.

If power is still present on the controller, there's no valid reading because there is a voltage present and resistance can't be measured accurately.

If you are testing between signal wires, then they should show 10k-20kohm resistance becuase your'e measuring between two of the pullups, basically.

If you mean the motor phase wires, then they should show at least very high resistance between each other. But if you had a problem with the phases on the controller, the motor wouldn't run at all, and would be hard to turn by hand if the FEts were shorted.

So seems we have a fault on blue sensor or its wiring. Do you think I can assume tne fault is in the motor /wiring or could it be a controller fault. Any test to decide which?.

Depends on exactly how the tests were done, as noted above.

 

[D-I-Y 82]

To amberwolf. Many thanks for your quick and comprehensive reply. Much appreciated.
When I referred to the 'supply' wires in my last post ,I was referring to the 3 'fat ' wires running via 3 bullet connectors from the controller to the hub motor.Should have called them phase wires.

When I referred to sensor wires, I was referring to the 5 'thin ' wires running via a 5 pin connector block from the controller to the hub motor.

So. Test1.
With motor disconnected from controller. (3 bullet connectors and 5 pin conector block all seperated) Measure resistance between 3 fat phase wires. Yellow-Green, Green-Blue, Blue-Yellow. All 3 tests show no measurable resistance. Quote amberwolf "Those should all show shorted together.......
1Good?

Test2
Setup as Test1.
Measure resistance between each fat phase wire in turn and motor case.
Yellow, Blue,Green. All show infinite resistance.
Quote amberwolf . " That's good....."
2Good?

Test 3.
Connect motor to controller. 3 fat phase wires via bullet connectors .Green to Green .Blue to Blue.Yellow to Yellow.and 5 thin sensor wires via connector block. All other connections made . Machine ready to run. Power on . Throttle closed.
Measure voltage on motor side of 5 pin connector block.
Red to Black 5v constant.
Yellow to Black and turn back wheel slowly backwards. Voltage cycles 0v-5v
Green to Black and turn back wheel slowly backwards. Voltage cycles 0v-5v
Blue to Black and turn back wheel slowly backwards. ZERO voltage constant.
Check as above but on controller side of connector block. Same results so no problem in connector block?
1Bad?

Test4. NEW.
Setup as above but disconnect 5 pin block connector. ie (disconnect 5 thin sensor wires to motor )from controller.
Measure voltage out from controller at 5 pin block with ongoing lead to motor disconnected
Red toBlack 5v constant.
Yellow to Black 5v constant.
Green to Black 5v constant
Blue to Black 5VOLTS CONSTANT.
3Good?
So fwiw it seems to me in my ignorance that there is a fault on the blue hall sensor wire or the sensor itself.
We have 5v at blue on the controller connector.(Ongoing lead to motor disconnected) A break in the blue sensor lead motor side of connector block would still leave us with 5v at the connector? What effect a short in the blue sensor lead or a failure of the Hall sensor itself would have I don't know. Can you help with that please.
Irrespective of that you have enlightened me on a number of points. Thank you!

 

[amberwolf]

So. Test1.
With motor disconnected from controller. (3 bullet connectors and 5 pin conector block all seperated) Measure resistance between 3 fat phase wires. Yellow-Green, Green-Blue, Blue-Yellow. All 3 tests show no measurable resistance. Quote amberwolf "Those should all show shorted together.......
1Good?

Yes, if those are the *motor* phase wires. If they're the controller phase wires, then that's bad.

Test2
Setup as Test1.
Measure resistance between each fat phase wire in turn and motor case.
Yellow, Blue,Green. All show infinite resistance.
Quote amberwolf . " That's good....."
2Good?

Yes, open-circuit phases to case/axle/etc is good.

Test 3.
Connect motor to controller. 3 fat phase wires via bullet connectors .Green to Green .Blue to Blue.Yellow to Yellow.and 5 thin sensor wires via connector block. All other connections made . Machine ready to run. Power on . Throttle closed.
Measure voltage on motor side of 5 pin connector block.
Red to Black 5v constant.
Yellow to Black and turn back wheel slowly backwards. Voltage cycles 0v-5v
Green to Black and turn back wheel slowly backwards. Voltage cycles 0v-5v
Blue to Black and turn back wheel slowly backwards. ZERO voltage constant.
1Bad?

Yes, the highlighted part is a problem, the rest is normal.

Check as above but on controller side of connector block. Same results so no problem in connector block?

This just means that there's no signal there. It doesn't tell you the connector block is good, just that it is probably not the cause of this specific issue. Most likely there's no problem there.

Test4. NEW.
Setup as above but disconnect 5 pin block connector. ie (disconnect 5 thin sensor wires to motor )from controller.
Measure voltage out from controller at 5 pin block with ongoing lead to motor disconnected
Red toBlack 5v constant.
Yellow to Black 5v constant.
Green to Black 5v constant
Blue to Black 5VOLTS CONSTANT.
3Good?

This means that the pullups inside the controller do have the proper voltage on them, so it's probably not the controller causing the hall sensor issue.

So fwiw it seems to me in my ignorance that there is a fault on the blue hall sensor wire or the sensor itself.
We have 5v at blue on the controller connector.(Ongoing lead to motor disconnected) A break in the blue sensor lead motor side of connector block would still leave us with 5v at the connector?

Correct. A break anywhere from the hall sensor itself onward would leave a 5v steady signal on the controller side of the break.

What effect a short in the blue sensor lead or a failure of the Hall sensor itself would have I don't know.

If the sensor is internally shorted to ground, or the signal wire is shorted to ground, then it would cause what you see.

If you leave the motor disconnected from controller/etc, and set the multimeter to continuity or 2ohms range, then connect the red lead to the blue hall signal wire on the motor cable, and the black lead to the ground (black) wire of the hall connector, it should read some high resistance (OL). If it doesnt', and reads low but not zero or something like 0.05ohms or similar, then the sensor is probably failed. If it reads basically zero or super low, essentially the same as just touching the red and black meter leads together, then it's probably a short between the black and blue wires. Such a short could again be anywhere between the motor side of the hall connector to inside the motor itself at the hall sensor leads. If the motor cable has ever been damaged in any way (usually at the axle exit), the short could be at that area.

 

[D-I-Y 82]

You're the bees knees amberwolf. I'll leave you in peace for a bit now and see what I can come up with. Cheers!