Front hub connector melted

Zephak

10 mW
Joined
Feb 11, 2022
Messages
24
Location
Willow, AK
When riding out on the lake this winter, I was throttling the 48v 1000w front hub drive quite hard when the bike died. There's 58v on the battery, no lights on the five wire throttle and a burnt connector on the hub wiring, pic attached. I thought I burnt up the 26Acontroller and bought a 48v1500w controller before noticing the burnt hub connection, but I may not need another controller but maybe new hub wiring

Could I get some help with a resource for the hub connector and a reference to checking wiring before I just go out and buy another front hub kit?
 

Attachments

  • IMG_20250404_090037595_HDR.jpg
    IMG_20250404_090037595_HDR.jpg
    393.8 KB · Views: 19
  • IMG_20250404_093926459_HDR.jpg
    IMG_20250404_093926459_HDR.jpg
    1.6 MB · Views: 20
Is that a bent pin in the motor connector? (blurry photo)

There are numerous other wiring problems. I see poor terminal crimping, exposed wires (damaged insulation), cut wires, etc.

Do you have the skills and tools to fix the wiring? If not, suggest you hire it out locally.
 
OK this is a standard 9 way motor cable, you can get either a flying lead which has the 9 way male connector one end and wires the other, or a 9 way male / female extension lead and cut the female end off and then strip back the cable. But you must check the female connector as well, I have had it where a friend wondered what was wrong with their front hub drive, I looked and it was these connectors coming apart.
 
Last edited:
Yes, looks bent and pins are pulled, better pic attached.

There aren't local mechanics for this kind of work.

I appreciate the honest assessment of my build. The whole battery compartment pic is also attached.
 

Attachments

  • IMG_20250404_101603984.jpg
    IMG_20250404_101603984.jpg
    253.2 KB · Views: 14
  • IMG_20250404_101740018_HDR.jpg
    IMG_20250404_101740018_HDR.jpg
    2.3 MB · Views: 14
I find that those 9 pin motor plugs are reliable at 22A, conditionally okay at 26A, and not suitable for 30+A.

The motor is probably fine, but you should replace the plug with a 5 or 6 pin one for the Hall and thermal sensors, plus three high amp connectors for the phase power.
 
Thanks @dgc @Chalo and @99t4
Um. I found an extension that would have the male and female ends and could imagine that the wiring could be straightforward.
If I went to a higher Amp connection, I think I would need a wiring diagram.
I'm not sure the 9-pin connection is the only problem.
 
I'm not sure the 9-pin connection is the only problem.
Agreed. And aside from the other faulty wiring conditions mentioned above, the battery construction is very sloppy and possibly more dangerous than it needs to be. Who built it?
 
I'm not sure the 9-pin connection is the only problem.
The fact that it's burned tells you it's at least part of the problem.
 
Someone who is me built it.
14s5p, , copied a layout from a picture, no welder here so I used the veuzend plastic connectors, some of which are cracked after several years of use.
 

Attachments

  • IMG_20250404_112020967.jpg
    IMG_20250404_112020967.jpg
    1.3 MB · Views: 7
Do the throttles, or controller or BMS typically go bad on builds?

It seems that since I see obvious damage on the 9-pin, replacing that first is best
 
Out of the many burnt phase wire connector I’ve seen on ES (which happens frequently), I have yet to see an example where it wasn’t either poor contact between the connectors, or just cheap connectors that have some sort of bottleneck that can’t handle the rated current. If you replace the connectors, you might as well upgrade to something like the HiGo L10 connectors that can handle more current, or do as Chalo suggested, and go with a 6 pin for halls, and good quality bullet connectors for the phases.
 
Is that a bent pin in the motor connector? (blurry photo)

There are numerous other wiring problems. I see poor terminal crimping, exposed wires (damaged insulation), cut wires, etc.

Do you have the skills and tools to fix the wiring? If not, suggest you hire it out locally.
That's a spoke and a nipple.
 
Out of the many burnt phase wire connector I’ve seen on ES (which happens frequently), I have yet to see an example where it wasn’t either poor contact between the connectors, or just cheap connectors that have some sort of bottleneck that can’t handle the rated current. If you replace the connectors, you might as well upgrade to something like the HiGo L10 connectors that can handle more current, or do as Chalo suggested, and go with a 6 pin for halls, and good quality bullet connectors for the phases.
My twisting skill is quite nice. :D
And I got the good electrical tape for now.
However, do you know where I could get a kit with cut colored wires, hall sensor plugs and 5-pin flat ones and bullets n spades that are crimpable?
I have searched and come up dry. You?
 
OK this is a standard 9 way motor cable, you can get either a flying lead which has the 9 way male connector one end and wires the other, or a 9 way male / female extension lead and cut the female end off and then strip back the cable. But you must check the female connector as well, I have had it where a friend wondered what was wrong with their front hub drive, I looked and it was these connectors coming apart.
I've used those cables with 30A many times with large geared motors without problems. In fact a couple of times the cheap phase wires coming out of the controller melted, leaving the motor cable intact, so I don't think it's a simple case of just overloading the cable at 26A. I think there's a fair chance that it wasn't pushed all the way in. There's a marked line that the outer must reach. Often they go tight before the line is reached, and 1mm short can cause issues. You can see the line in your photo. Conveniently, the arrow points to it.
 
Could someone give me a suggestion for probing the wires that come out of the controller that lead to the motor. Maybe there's a sticky somewhere?
My first thought was to hold negative on the voltmeter to battery negative, turn on the throttle and check voltage on each wire, but I don't want to risk without knowing.
 

Attachments

  • IMG_20250405_101817941_HDR.jpg
    IMG_20250405_101817941_HDR.jpg
    250.6 KB · Views: 4
It's fixed...The 60a fuse looked good but wasn't. There was occasional continuity on it but it wasn't passing enough current. A new one solved it.

I will look into a new 9-pin and maybe rework the battery.

Thanks for the help here! I really appreciate it!!
 
👍

If you’re using the existing connectors for now, try to clean them really well in order to maximize the metal to metal contact.
 
It's fixed...The 60a fuse looked good but wasn't. There was occasional continuity on it but it wasn't passing enough current. A new one solved it.
FWIW, with that kind of fuseholder, it's more likely that there is an issue with the holder itself, most often a wire-connection issue (poor crimp or solder, etc). Can also be the barrel cups on each end not being a good fit for the fuse. Happens with other fuseholders, too.
 
Back
Top