Repair ABS sensor harness?

[timsch]

Anyone had success splicing in wire to repair a buggared ABS sensor harness? My son didn't clip the harness back into the retainers on the struts after the last job and it got abraded by the wheel apparently. It's in a pretty harsh location.

 

[Nuje]

I'd go to a scrap yard, find an intact wire and cut it near the body so you have much length as possible, and a fully intact bend between those two retaining nubs.

Then, cut your existing wire in roughly the same place and splice in (waterproof heat-shrink butt connectors) the one you cut off the scrap car.
Wrap your splice in wiring harness tape and maybe some heat-shrink tubing as well.

 

[compu_85]

Is the wire broken? If not, i'd goop it with liquid electrical tape and keep driving.

I'd also price out a new sensor. What car is this on? They generally aren't expensive.

-J

 

[timsch]

Mk4 Jetta. Wire's not totally broken. Maybe half of the strands left on the worst wire if I'm lucky. I separated them as well as I could and wrapped some pieces of tape around each exposed section of wire, then wrapped the whole bundle in electrical tape. I'll wrap this again with some self adhesive silicone tape since I know the electrical tape itself won't last.

Another less abraded section I gooped some gasket maker i have that doesn't seem to get hard around the missing wire insulation and then sealed any gaps in the outer sheath with E6000 adhesive - basically stuff i have around the garage.. I've never heard of of liquid electrical tape, but that seems more proper than what I did.

Harness was ~$130 new, so I'll hold off on replacing it for now. I posted a WTB, so maybe I'll get lucky with someone parting out one of these.

 

[ts888]

Is this sensor side or harness side? I think idParts sells harness side repair connectors.

 

[timsch]

Damage is at the section where it is held @ the strut. Picture at top shows the two snap-in pieces on the harness.

 

[Nuje]

Definitely worth a try going with the "patch what you got left and see if that works" approach.

I don't know (read: understand) exactly how the ABS sensors work, but there are some systems on the car (e.g. airbags) where the controller is sending a signal and expecting back a certain resistance; and if it doesn't get that resistance - it shuts down the system and throws up the error light. Airbags will often fail with a "resistance too high" error just due to minor corrosion or the like on a terminal. If the ABS system is like that, having half of the wire's strands missing in one spot would probably light up the error light.

 

[timsch]

True enough, Nuje. It was easy enough to try. I'll find out this week whether it was effective or not. I figure it's a short-term solution one way or the other.

 

[Gothmolly]

...
I'd also price out a new sensor. What car is this on? They generally aren't expensive.

Why? The sensor is good, the wire is bad.

 

[compu_85]

I was conflating this with my Benz where the sensor and harness are combined. Oops...

-J

 

[Zak99b5]

Wheel speed sensor is basically an oddly-shaped guitar pickup. It creates a (very small) voltage as the tone ring passes by it (instead of a vibrating steel string). The Hz of that voltage is dependent on wheel speed, so that is what the abs controller is looking for and using.

The voltage is super weak, so it doesn’t require much wire to carry it; however, any poor connection will cause it to drop out. So if it’s still working, I’d not go looking to splice anything. Just insulate and protect it as well as possible and motor on.