ADL speed reading

[Billzilla]

Like the other thread, I have an ADL in one of my road cars and I've been driving it recently after it sitting on the hoist for about four years.
First couple of drives, the speed varied from fairly low up to a good 900 km/h or so. The car is fairly fast but certainly not in land speed record territory. Then the last couple of times it's been on the road it's been reading zero the whole time.
Any suggestions of where to start fault-finding please?
Ta!

[David Ferguson]

You might want to start by sharing your config, or some logged data.

Possible causes:
- misconfigured software
- wiring fault (corrosion at connectors, physical damage to wiring or connectors
- failed wheelspeed sensor.

[Stephen Dean]

I'm with David on this one, but I would be concentrating on the wiring and sensor itself, unless a change has been made to the configuration in the dash recently.

[Billzilla]

I'm with David on this one, but I would be concentrating on the wiring and sensor itself, unless a change has been made to the configuration in the dash recently.

No changes for over a decade at least. The wiring is quite difficult to get to, but I'll have to ...

[David Ferguson]

I'm betting you have have some house guests (like mice) that liked the yummy wires... Difficult for you to get to, perfect for mice...

[SprinterTRD]

Depending on your sensor location and sensor, A possibility may be that Iron filings have gotten into the sensor teeth causing extra pulses

[Billzilla]

Ta Steve, I'll check that out as well.
It's a pain in the rear getting the Fraser onto the hoist but I'll just have to do it.

And FWIW ...

https://www.youtube.com/watch?v=vlphHbY3mqA