Caterham Speedo - Should the LED flash

[JasonNT]

Hey Folks,

Been trying to debug a speedo issue on the Caterham Roadsport SV. The speedo has been failing when its hot, and now its given up the ghost entirely.

When the ignition is on the sensor has a little LED on the back of it. Should this LED flash when the teeth pass by it? At the moment its on constantly, which I think might be the Sensor gone pop, but need to confirm it.

thanks

Jason

[anonymous-user]

I believe it should flash, yes.

Not an uncommon failure. It may be just adjusted to be too close, though you’d still expect it to flash when the wheel was rotated slowly.

The gap should be around .9/1.0mm.

[BigCol]

Yes, the LED on the end of the sensor should flash when the wheel rotates. If it doesn’t (LED permanently on/off) chances are the gap needs adjusting.

If LED always off, also check the immediate wiring (can fracture) or do the earth mod Caterham recommend (their workshop note WN572 refers)

The former is most likely, is a common issue and easy to fix.

[JasonNT]

I actually have the opposite issue the sensor stays on continuously regardless of distance. Think it's just gone kaput.