Aaaaand we're back, because as all Disco 2 owners know, there are actually three certainties in life - death, taxes and the three amigos.
I started to get intermittent amigos a while back, usually when turning hard left, so probably a broken wire. Nanocom reported 'front right sensor intermittent', so I ordered a new sensor.
New sensor arrived and although the cabling all looked new, the sensor itself had been filed around the edge and the centre tip was exposed rather than covered. The mounting bracket also had a witness mark where the screw had been. Contacted the supplier and they sent me another one.
View attachment 256867
I stripped the brake off the front right corner and confirmed the broken wire by connecting a multimeter to the sensor connector and set to Ohms. This read about 1000 Ohms until I moved the wire just above hub cable bracket, at which point it went open circuit.
I removed the old the sensor, fitted the new one, put it all back together and went for a test drive.
Bong bong bong! Damn.....
Nanocom now says 'front right sensor output too low'. I had checked the new sensor with the meter and it looked OK. Maybe it just didn't pulse when the hub teeth went past it, but how to check it? In the end I got a fan from an old PC power supply and pushed a small split washer over one of the blades and connected it to a 12V battery. With the Nanocom display showing the wheel speed page and holding the sensor close to the path of the washer on the spinning fan, I could see a wheel speed of about 10mph (not enough hands to take a photo of that).
View attachment 256865
So while I was pleased my test worked, it didn't show anything apparently wrong with the sensor. Eventually I decided that, as I knew the old sensor head worked, I'd cut the new one off and solder the old one to the cable - success! A test drive cleared the fault and didn't come back when turning full lock.
I've no idea why the new one didn't work. it looked to be exactly the same sensor depth as the old one, so should have ended up in the same place in the hub. I suppose the cheaper sensors are just a bit of a lottery, mostly they work but every now and then you get a rogue one.
