How important is this wire on my Xantia?

Napoleon · Post by **Napoleon** » 06 Jun 2010, 12:17

It's located behind the fuel filter housing, and appears to be secured with some blu-tak.

Pics:

And a closeup:

spider · Post by **spider** » 06 Jun 2010, 12:44

I'm not that familiar with these.

That is either the temp sender (or overheat sensor) for the dash, (different one if you have AC , bitron sensor maybe?) or the ECU temp sensor although AFAIK the electronic XUD's do not use this.

Just to confirm, it is screwed into the thermostat housing yet ?

You do need it really anyway

it was there for a purpose.

If I had to take a guess I would suggest it was the overheat sensor but I cannot be 100% sure.

Post by **CitroJim** » 06 Jun 2010, 12:51

spider wrote: If I had to take a guess I would suggest it was the overheat sensor but I cannot be 100% sure.

Assuming non-aircon, non ECU controlled pump, I'd agree, especially if the temperature gauge is working normally.

The purpose of it is to light the red light in the top of the gauge and to bring on the STOP light in case of overheating.

Tim, can you confirm the temperature gauge is OK and that you don't have aircon?

EDIT: the reason it's gone like it has is because the sensor has allowed antifreeze to seep out of the top of it and into the wire.

If you pop the connector off I'd expect to see a lovely mess of corrosion inside it.

Napoleon · Post by **Napoleon** » 06 Jun 2010, 13:02

@ Jim, no problem with the temp gauge (shows normal readings and nothing to suggest overheating problem), and no aircon fitted.

spider · Post by **spider** » 06 Jun 2010, 13:14

Just to add, some models (probably those without AC) still have two sensors.

One for the gauge and another for the overheating light itself. My 205 has two (one for each function)

I've cleaned your picture up a bit so its easier to see for anyone else:

Napoleon · Post by **Napoleon** » 06 Jun 2010, 18:30

CitroJim wrote:
spider wrote: If I had to take a guess I would suggest it was the overheat sensor but I cannot be 100% sure.
Assuming non-aircon, non ECU controlled pump, I'd agree, especially if the temperature gauge is working normally.

The purpose of it is to light the red light in the top of the gauge and to bring on the STOP light in case of overheating.

Tim, can you confirm the temperature gauge is OK and that you don't have aircon?

EDIT: the reason it's gone like it has is because the sensor has allowed antifreeze to seep out of the top of it and into the wire.

If you pop the connector off I'd expect to see a lovely mess of corrosion inside it.

Suggestions for repair/improvement?

spider · Post by **spider** » 06 Jun 2010, 19:38

Just to clarify, the 'overheat' sensor is a separate function from the gauge by design.

You could briefly (assuming it is a single wire) short it to earth and watch for the warning light to appear, although if its for something else that could cause damage, unlikely but it is possible.

I would suggest unplugging it, (watch that clip as its the annoying one by the looks of it, I can't see the other end) to make sure it does not disappear.

Clean the terminal up on the sensor itself and do the same for the plug. If the plug is 'really' bad, go and cut one off with a few inches of wire from the scrapyard (same colour for sanity's sake) and solder it on, using heatshrink for a nice finish. Obviously remove a couple of inches of your existing wire to remove any chance of the corrosion spreading up the wiring by oxidisation.