Julet harness

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Deleted member 4366

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A while ago I had to do some wiring on a bike. It had one of those waterproof Julet harnesses (4 into 1). Here's the detail if anybody needs it. You have to zoom in to see the colours of the wires in the small circles:

harness.jpg
 

Gingafuzz

Just Joined
Apr 14, 2017
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Hi Dave,
Unfortunately mine is slightly different. However, applying a little logic using your diagram, I think that the added pin on my display connection is simply the switch signal for the front light. The pin out location which was the controller power on your diagram is the light switch signal.

Therefore it seems logical that the center pin on my connection is the LCD power and they have moved it to the center pin to allow the light switching wire to be connected on to the other pin. That's assuming everything else is in the same location as it was on your diagram (which they seem to be).

The added annoyance is that some of the colours are different!
I have no blue or yellow, but I do have grey and orange.
I have added a couple of pics to illustrate easier.

I've cut the five pin jst connector off in order to test the pin outs more easily.
The three way jst is the throttle connection and the single brown connection is the brake signal.
image.jpeg assuming that the throttle connection follows the usual protocol, the middle wire which is grey with a black stripe, ought be the signal wire and the pink and white wires ought to be Vcc+ and Vcc-.

Going back to the 6 pin display connection, it seems reasonable to assume that the green wire, since it's in the same position and the same colour as your diagram is the LCD tx. This leaves the Orange (similar to yellow with a little imagination!) wire which it seems reasonable to assume is the LCD rx.

There are quite a few assumptions there!

My diagram shows the location on the plugs of the wire connections as they are as tested with a continuity test on my meter.

image.jpeg
 
D

Deleted member 4366

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I solved mine by sticking a sewing needle in the pin holes and probing the other end to see which was connected to which. Next, I connected it to the controller, powered it up and used my meter to see which pins were ground, which were 5v and which had battery voltage. I did that to both the controller's connector and the harness connectors. After that, I opened the controller to identify the wire that powers the controller from the LCD, which is soldered to a pad joined to the big resistor. I didn't have the wire for the lights, which would normally go to a small mosfet or transistor. All the rest can, therefore, be identified by logic.
 

Gingafuzz

Just Joined
Apr 14, 2017
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I tested in a similar way although I just ground down the + tip of my meter...I found pins a bit fiddly!
I haven't run a powered test yet though.

When you say "powers the controller from the LCD" do you mean a switching signal which enables the controller to be turned on and off from the LCD?....that might be the wire which Risunmotor refer to as 'lock control' on their diagram.
That would make sense because if it's simply an on off signal, it's likely to be the same signal wire which goes to their combined optional throttle/key switch to do the same thing, hence 'lock control'. I guess they assume we call everything in English which requires a key a 'lock'!

On a side note, I've just ordered a 36v 10amp switch mode power supply for an 'off the bike' system testing rig I'm planning on building. It's really intended for powering led lighting but I'm hoping that 10amps will be enough to power a 250w motor hub for short tests with practically no load on it. Do you think it will be man enough?
 

Woosh

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May 19, 2012
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I tested in a similar way although I just ground down the + tip of my meter...I found pins a bit fiddly!
I use cushion pins to probe these connections:

 
D

Deleted member 4366

Guest
I tested in a similar way although I just ground down the + tip of my meter...I found pins a bit fiddly!
I haven't run a powered test yet though.

When you say "powers the controller from the LCD" do you mean a switching signal which enables the controller to be turned on and off from the LCD?....that might be the wire which Risunmotor refer to as 'lock control' on their diagram.
That would make sense because if it's simply an on off signal, it's likely to be the same signal wire which goes to their combined optional throttle/key switch to do the same thing, hence 'lock control'. I guess they assume we call everything in English which requires a key a 'lock'!

On a side note, I've just ordered a 36v 10amp switch mode power supply for an 'off the bike' system testing rig I'm planning on building. It's really intended for powering led lighting but I'm hoping that 10amps will be enough to power a 250w motor hub for short tests with practically no load on it. Do you think it will be man enough?
It's not a signal wire. it provides the 300mA for the controller's CPU and sensors. It's the wire they often refer to as Key-lock or anti-theft. when you press the power button on the LCD, the first thing the CPU does is to latch that wire to the wire from the battery. When you press the power button again, the CPU de-latches it. All LED and LCD displays work like that on Chinese bikes.

You can test an e-bike with a 2 amp charger as long as you keep the wheel in the air, so a 10 amp power supply would be more than enough.
 

Gingafuzz

Just Joined
Apr 14, 2017
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England
Thanks Dave,
I'm learning all the time which is why I'm really enjoying this new (to me) hobby! I'm an engineer for a living and the tinkering is what it's all about for me, riding the finished product to work is just a bonus.

Although my reckoning was a bit off, the result I'm looking for appears to be the same, which is that the center grey wire on the LCD coupling must be the one which should marry to the blue 'lock control' wire on the controller.
I'll do a powered test (once my power supply arrives) just to be certain that I get what I'm expecting out of the pins and then I think I'll be ready to wire up!

I already have a 5amp charger, so the £22 I've invested in the 36v 10amp power supply was probably a waste then, it won't break the bank though and at least I can hav it dedicated to my testing rig.
 
Last edited:

SkottieB

Just Joined
May 30, 2020
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A while ago I had to do some wiring on a bike. It had one of those waterproof Julet harnesses (4 into 1). Here's the detail if anybody needs it. You have to zoom in to see the colours of the wires in the small circles:

View attachment 19524
This was EXACTLY what I needed thank you SO much!!! Wow. Almost a week of searching but my bike is now working thanks to this very post!!F88283B0-6B74-44BC-A374-124EBAB4AE08.jpeg
 

Dozzo

Finding my (electric) wheels
Dec 26, 2020
5
0
A while ago I had to do some wiring on a bike. It had one of those waterproof Julet harnesses (4 into 1). Here's the detail if anybody needs it. You have to zoom in to see the colours of the wires in the small circles:

View attachment 19524
I've got a greenedge cs2 16 bike. Water got into the 1 to 4 block. I've been trying to bypass the multi block. This layout seems to have no relationship to mine although the wire colours are the same. Any one anything about these.