as title really, had a quick read on this forum before posting.

Our 500x recently the outside temp gauge has started flatlining, displaying -- and since then our air con is only blowing hot air. previously was ice cold so I don't think it needs regassed currently.

Thankfully on another thread a nice chap posted a link to the sensor itself (ebay 9.99 job)

but I am hoping someone can provide a how to in terms of replacing it - I've helpful family that are mechanically minded so having instructions on doing it may save a small fortune vs labour at a garage.

Thanks in advance!

They are normally built into the mirror housing so you may need to remove the back cover or the whole mirror itself from the car and then solder the new Sensor into the existing wiring loom

I recently replaced my faulty sensor with the one from the well-known auction site. Removing the external painted trim just required a bit of courage and some decent plastic trim removal tools. Once you pop one corner of it, you can progressively work your way around the clips and it comes away. The depth of the sensor head makes it quite challenging to remove it from the base of the mirror as there's insufficient headroom above it to lift it out cleanly. If you could remove the mirror glass mount, the job would be a doddle but I couldn't or rather daren't so I just cut the head off the old sensor with a pair of flush cutters to make it smaller for removal. Fitting the new one required prizing the mirror base a bit with the trim tools to create enough space to manipulate the new one into place. Thereafter I simply cut and spliced the two new sensor wires in. They are not polarity sensitive so you can't do wrong. There is no need to remove door cards etc, all work can be done inside the mirror housing. It's an easy enough job which would be a lot easier if you could remove the glass assembly without any fuss.

G1WLM, I ve just read this and now have the confidence to do this myself