Xantia TD Speedo and Temp Gauge Sudden Death

[ecohouse1]

Morning Chaps

Was driving in this morning in my 99 Xantia TD and noticed that the speedo wasnt working - just sitting on 0. It did occasionally flick up to the speed I was going but quickly died. I noticed the temp gauge was also sitting on the deck all the way in, although a couple of points crept up to 65 degrees but slipped back to the rest point. Never had this before. I am hoping its just an earth or dodgy connection as I believe its an electronic speedo not a cable job like the BX. Not been near the dash for any work or the gearbox, so a bit perplexed why this could have happened. I am assuming that if the speedo is working some of the time it cant be a fuse?

Any pointers as to possible causes?

Many thanks

Alan

[CitroJim]

Electrical. First check is the connection to the sensor on the RH side of the diff.. It's in an exposed spot and can suffer.. Also the cable can get damaged from heat from the exhaust manifold making the insulation go hard and then crack/short-circuit..

The temperature gauge may be unrelated and a red herring for this issue...

As always, if you need wiring diagrams, just shout...

[ecohouse1]

Thanks Jim, I was fording some of the aberdeen floods a few weeks ago - some up to gearbox- well up to the top of the sill with the suspension at full height (it was at this point I retreated!)
I wouldn't imagine that would have done the sensor any favours. Is that RH side of the diff looking at it from the drivers seat? Are they easy to remove from the gearbox? Cheers, Alan

[CitroJim]

The sensor is on the RH side as you sit in the car and is on the side of the diff with the long driveshaft Alan, the Offside...

Very easy to get to from underneath whilst abiding by all the mandatory safety precautions when working under a hydraulic Citroen..

The sensors themselves rarely fail and if they do replacement is easy (one 10mm stud and a bit of fiddling) plus they're common right across the range from BE3 'boxes right up the HP20 automatics!

[ecohouse1]

Interesting. On getting home tonight I removed the temperature sender plug and refitted it but no difference. When the ignition key is turned to on pre start. The temp gauge registers normal but as soon as the engine starts the temp gauge drops to base. Any ideas what can be causing that? Very odd.