Throttle issue

UrbanPuma

Esteemed Pedelecer
Sep 11, 2007
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They're all a bit low, so there could be something wrong with your meter. If it were just the full throttle signal, I would have said that you've broken the end-stop, but I can't draw that conclusion when the other two are low as well.

Have you got a new AA battery you can ckeck? It should be close to 1.5v. If it's lower, your meter isn't reading right.
Oh. I only received the meter today, so assumed it was new. I'll have to get a new one and try again.

I did notice while riding the bike today that in pedal assist mode there wasn't any oomph when I engage the pedals anymore, and as mentioned before not much twisting is required to get to full throttle now. Any suggestions as to the cause?
 

UrbanPuma

Esteemed Pedelecer
Sep 11, 2007
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No.

How's the power from the pedal sensor?

The only way to confirm whether the throttle is working OK is to measure the voltage on the signal wire, while you operate it. Show us the connector if you need any help with that.

As I said above, it's too easy to break the end-stops, which can do all sorts of weird things regarding power. Normally you'd know that you'd done it because there would have been an event that caused it to break: throttle was working OK, big bump, a few swear words, then the throttle isn't working like it should. In other words, it doesn't happen while parked in the garage.
I think the probes are too big...it's really difficult getting them in to touch
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
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West Sx RH
Use sewing pins or needles to shove up the back of the connector and apply the probes to the pins/needles.
 

UrbanPuma

Esteemed Pedelecer
Sep 11, 2007
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Sorr, I made a typo. It should be the black and white wires. Make sure that the probes are reaching the metal in the connector.

Using the red wire, it should still have worked. You should have got about 4v with the throttle closed and 1v when fully-opened.

Using the black and white wires, you should get around 1.2v and 3.8v.
Sorry, it has been a while - I was snowed under and have only just managed to get round to this.

Readings are as follows:

Black (ground) + white (signal) wires
Closed = 0.86v
Open = 3.55v

Black + red wires
Closed = 4.29v
Open = 4.29v

Hoping you can help.

kind regards,

urbanpuma
 

vfr400

Esteemed Pedelecer
Jun 12, 2011
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Basildon
Sorry, it has been a while - I was snowed under and have only just managed to get round to this.

Readings are as follows:

Black (ground) + white (signal) wires
Closed = 0.86v
Open = 3.55v

Black + red wires
Closed = 4.29v
Open = 4.29v

Hoping you can help.

kind regards,

urbanpuma
Those readings show that your throttle is working correctly. can you remind us what the problem is that you're trying to solve?
 
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UrbanPuma

Esteemed Pedelecer
Sep 11, 2007
675
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Those readings show that your throttle is working correctly. can you remind us what the problem is that you're trying to solve?
Sure. The throttle feels loose/low power when twisting and is slow to engage and get up to speed.

Also, when I switch the bike on and turn throttle the motor keeps cutting out intermittently. After turning the key several times it starts but sometimes it just makes noise trying to engage with motor then cuts out. It's gone dead then started working again after 1 hour or the next day. Sometimes, it makes juddering noise on startup and yesterday while pedalling I applied throttle and heard a loud juddering noise then it cut out. After few key turns on/off it worked again and I was able to continue riding home - this keeps happening each time I go for a ride
 
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vfr400

Esteemed Pedelecer
Jun 12, 2011
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Juddering problem is nothing to do with the throttle, neither is slow pick-up. You have a problem between the controller and the motor. First, check that the moulded connector near the motor (if you have one) is in all the way to the line, not just in tight. Secondly, check that you haven't nicked the motor cable where it comes out of the axle, Third, check that all the motor connectors at the controller are tight.
 

UrbanPuma

Esteemed Pedelecer
Sep 11, 2007
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Juddering problem is nothing to do with the throttle, neither is slow pick-up. You have a problem between the controller and the motor. First, check that the moulded connector near the motor (if you have one) is in all the way to the line, not just in tight. Secondly, check that you haven't nicked the motor cable where it comes out of the axle, Third, check that all the motor connectors at the controller are tight.
Ok, I'll check these today. What about the key having to be turned on and off several times until the bike starts working again - what could this be, same issue or different?

Also, what could cause the noise it makes trying to engage?
 
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vfr400

Esteemed Pedelecer
Jun 12, 2011
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Basildon
Ok, I'll check these today. What about the key having to be turned on and off several times until the bike starts working again - what could this be, same issue or different?

Also, what could cause the noise it makes trying to engage?
Noise is when the pulses from the controller are not synchronised with the motor. Often, the controller will not fire any pulses if it detects a problem, but if you have a marginal problem, you'd get the symptoms you describe. You have to find the cause. Running it like that can blow the controller.
 

UrbanPuma

Esteemed Pedelecer
Sep 11, 2007
675
43
Noise is when the pulses from the controller are not synchronised with the motor. Often, the controller will not fire any pulses if it detects a problem, but if you have a marginal problem, you'd get the symptoms you describe. You have to find the cause. Running it like that can blow the controller.
I've checked the controller and tightened the phase wires as yellow was not as tight as others - these connectors are not great (would like to change them).

I also pushed in one of the battery connections as there was some give there. I'll take it for a spin to test it tomorrow.

Thanks