HESC issues

TPH

Just Joined
Nov 25, 2021
4
0
Hi to all. Newbie here, so please cut some slack if format is wrong.
Currently a 3 ebike house. I have a Haibike Cross 6 2 years old and still great. My wife has just got a Cube Touring Hybrid Pro easy access, this also seems good so far.
Problem child is the Haldords Carrera crossfire ladies that we have had for a few years.
Battery connector terminal housing broke, but was able to repair, had to strip down in that area to get access. Since putting back together the speed reads zero, regardless of actual, and bike turns off after 10 minutes, even if in use.
I guess the bike thinks it is stationary and goes into auto off.
I have looked for damage wires it the area, but can not see anything obvious.
Believe the speed sensor is in the hub, the wire into the hub looks undamaged and the plug looks fine, all contacts present and nice and shiney.
The power side of things is all good. Bike rides well and the walk assist is all good. Just the speedo issue.
Any tips or pointers would be gratefully received.
Tim
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
19,990
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West Sx RH
Likely without a speed reading the shut down may be due to either a failed hall sensor, speed magnet in the hub has come unstuck or broken wire.
One can test the Hall with a meter via the motor wiring. Find the thin Black hall wire to the motor and place your probes on that one and the speed sensor wire, rotate the wheel slowly backwards by hand and one should see the voltage switch on & off/5v - 0v for a functioning hall. If this is ok then either the hall magnet has come loose or the wire is broken, if the hall doesn't switch then it has to be replaced.
If one gets no voltage reading at all then it is a wire connection issue.
 

TPH

Just Joined
Nov 25, 2021
4
0
Thanks for getting back to me. I can certainly check that out with a meter. You said the thin black wire and the speed sensor wire, do you know what colour that one is. Also are you testing at the hub plug or does the system need to be powered up, and if so where in the system do you insert the probes. Is the 5v derived from the battery power or generated withing the hub?
I have presently got the whole system removed from the bike and on the bench so testing should be relatively straight fwd.
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
19,990
8,172
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White is common to be used as the speed wire colour.
Black & Red are the Gnd & 5v, Blue,Green & Yellow are the motor halls so the ninth colour is the speed hall. The three thick colours are motor phase.
The system needs power so test from the controller motor connector, if the connector is a waterproof type then it is very hard to do so without making up a a special Y cable.
5V is generated via the 5v rail from the controller.

If one can't access the wiring or make up Y lead then one has to try and use the wire points from the controller pcb.
If the nine wire motor connector to the controller is a block type then one can use a pair of needle or pins stuffed in to the rear of the wire and then use these to contact the probes with, just don't short the contacts at any stage.
 
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TPH

Just Joined
Nov 25, 2021
4
0
Ok then. I had to use the multimeter and needles technique and here is what I got. Piercing the insulation of the cables as they exit the controller below the battery housing. Confirmed red wire and black wire 4.9v which was constant as you would hope.
White wire and black wire 3.0v constant whilst rotating the wheel in either direction.
Does this point towards an issue within the hub.
I did try to strip the hub down to get access to the wiring but without much joy. The opposite side of the hub can be accessed once the cassette and free hub were removed, but this only gives access to the planetary gearing.
The side where the cable enters through the side of the axle proved more tricky. I removed the key way block fixed with a grub screw which exposed the axle and a plastic surround. At this point, and with the other side of the hub exposed, I cant work out if anything else is preventing the axle pushing through. it is obviously passing through a bearing, but I was reluctant to press too hard in case there is something holding the axle in place. presumably the motor windings and the speed sensor and magnet are housed in this side.
Sorry if this is long winded, just trying to provide detail and hope you can offer advice
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
19,990
8,172
60
West Sx RH
The HESC system uses a different waterproof motor connector then other systems, generic China ones all tend to use the Julet 9 pin connector.
For bike with all moulded connectors then the easiest option is if poss buy another motor or extension cable to make a testing cable, chop it in half and bare all the wires on both sides. Use a typical a 15/30a strip with nine screw ports and wire each side of the cable as a pair in to each port. then use the screw as your probe contact.
When finished remove the testing cable and reconnect as normal.
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
19,990
8,172
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West Sx RH
4.9v is good, likely the meter calibration is a lightly erroneous but not hugely.
3v isn't good nor that is doesn't switch so looks like a new hall sensor is needed.
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
19,990
8,172
60
West Sx RH
Someone on here may have already opened a HESC hub up, a forum search may show up a thread.
The axle is fixed, once the planet gears are exposed the hub is held in by strong magnetic force field. The motor has 16 - 20 magnets around the circumference and they form a force field to the motor coil, it may need a puller to separate.

Again try a internet search for geared hub repairs/removal.