Hi guys how can I access the wiring for wheel speed sensor from the rear left tyre to the abs unit. I have been having intermittent ABS issue, all the mechanic parts seem fine. So far the mechanic hasn't checked the wiring. If there wiring is accessible I could have a look for any possible damage in the wiring. Thanks.

On a mk1 it goes from sensor connector along rear beam, then up through into the cabin under the rear seat, then along to front of cabin, then through firewall (deep behind steering wheel) to ABS controller in engine bay. I imagine a mk2 is similar.  There are some connections/splices in the loom in the area under the rear doors, I think, which can get wet on leaky mk1s but I don't think the mk2 suffers the same troubles with leaking rear door carriers?

The only really easily accessible part is the bit near the sensor connection, and also the most likely to get damaged mechanically.

Thanks Wino, I did notice a while back when I opened the rear door, lots of water poured down through the door. I have been having this ABS problem for a while now it only comes when you drive for certain amount of time. Turn off the engine, and it's gone again to be back after a while of driving. My mechanic ordered a new sensor which also had the same issue so he replaced it back with the original one. He swapped the rear right and left hubs to see if the problem would change place but no still in the rear left. Because the problem is intermittent he says that the continuity test might not help with the diagnosis and has recommended me it wait until it develops permanent fault. I had posted the issue a while back and was hoping to get a reply off you. Thanks.

If you open the rear door after rain do you see little puddles on the rubber seal like in this photo?

On the mk1, if you do see those puddles, it will be leaking down between that rubber seal and the plastic trim just inside it, and there is wiring running along under that trim.  This is where another member  (with a mk1) found corroded wire splices between the ABS sensor wiring and the main interior loom.  It may be a good idea to investigate under this plastic on the left side of your car, if you do see water there. I really don't know if the mk2 even has the same arrangement though.