No instrument readings - 2017 310S

[Jakeypoppet]

Hi All,

I had a speedo dropout problem with my almost new 310 (sigma engine) that was fixed recently in service at Caterham South by moving speed sensor on the axle - but this dropped out (zero reading) again today when I went over a bump.

A few minutes later, I lost all instruments - revs, temp, pressure, fuel. Also the indicators don’t work and the odo readout on the speedo has gone blank (whereas before, it still read the mileage). The lights and hazards are fine as are the instrument/switch lights and the car runs and starts no problem. The heater fan was on at the time.

any ideas? I’m thinking it’s just a bad connection somewhere...

Thanks in advance.

jake 

[Jonathan Kay]

There's a known fault with wheel sensors and their wiring that can affect other circuits.

Recently discussed here with suggested approaches to fixing it.

Have you got the appropriate wiring diagram and a multimeter?

Jonathan

[Jakeypoppet]

Hi Jonathan,

thanks - just read the other thread - it does seem that my problem is linked to the very recent speedo sensor dropout. Perhaps it shorted and fused another circuit (or maybe the instruments are on same fuse). Since it’s drivable (but no indicators) I’ll take it back to caterham tomorrow - luckily they are just round the corner from my work :)

I’ll post on here if they figure it out. Otherwise, I’ll buy a multimeter!

 

[Jim 123]

Any fuses blown? May not be directly Iinked to speedo.

[Doug phillips]

Exactly the same thing happened to someone at the Dunsfold handling day, but I don't know if he managed to fix it.

[Jakeypoppet]

I can confirm that it was the speed sensor. This had shorted and then instrument blown fuse - same circuit as the speed sensor apparently. Caterham have fitted a new style speed sensor (car is only 6 months old - 1200 miles) and replaced the fuse and all is working. Will have to see whether new style sensor is more robust :)

[Jonathan Kay]

Thanks for the update.

Jonathan

[ChrisC]

The problem in my view is the way its wired and the location of the connection to the loom.   All the flex needed for the suspension is applied to the thin wire coming from the sensor.  A connector located on the wheel sensor bracket with a lead between the bracket connector and the loom would mean the wiring breakdown would not kill a very expensive sensor, but a much cheaper lead. 

But still Caterham missed a trick, locate the wheel sensor inboard near the diff and there would been no need to have the wiring move with the suspension at all.