407 coupe air con temperature gauge

[Sushi5734]

Hi,

I've had my Peugeot 407 coupe 2.2 petrol for about 5 months and I haven't needed/wanted to use the air conditioning until this week. The air con produces absolutely no cooling effect on the lowest temperate. I have a model with dual zone climate control. I have had a few minor issues with various sensors triggering alarms intermittently and took back to the garage I bought it from. I have had a few pugs over the years so I'm well used to this =D I mentioned that I had noticed that the temperature reading on the centre console display always seems to be wildly inaccurate, usually -10 to -15c which is obviously 20-30c out. The garage said that is a temperature sensor in the door mirror (a small black rubber nodule) and that this was faulty. The car was quite cheap with low mileage and overall the garage have actually been pretty decent. They sorted out a few issues so air con seem pretty trivial...until this week!

I was going to get my aircon re-gassed the week but I was wondering if this temp gauge is acting as a thermostat and would stop my air con compressor from kicking in, as the car would sense that its very cold outside or is this temperature sensor on the wing mirror just for driver information? It's obviously not molten hot weather at the moment but driving in motorways with the windows closed is really stuffy and the fan by itself just isn't cutting it.

If this sensor on the wing mirror is intergral to aircon/climate control, how much roughly am I looking at to get it sorted?

If it isn't, presumably its just needs a regas or there is some other issue with the aircon.


Thanks

[Hell Razor5543]

The external temperature sensor really is used by the air con (I know that other forum members have had A/C issued caused by this sensor not working), and replacing it has resolved the issue. New ones are not too expensive (a trawl through ebay shows them from around £10), but I don't know how easy it is to fit them.

Oh, to the forum, by the way.

[Sushi5734]

Thank you for the welcome and the information. =]

If the sensor is quite cheap then it's worth while getting it done. I'll try and find some tutorials to see if this is something I could do or if I'd need to hand it over to a professional.

Thanks again!

[Hell Razor5543]

I would suggest you go for a known make (as some of the cheaper parts don't always last too long), and avoid Euro Car Parts at all costs (they have the deserved nickname of Euro Crap Parts).

[GiveMeABreak]

There's not much that can go wrong with these and they are cheap enough to purchase. Your issue is going to be the fitting, as often it means cutting the original sensor wiring, leaving enough to splice in the new sensor wiring and refit.

The sensors are very common and cheap - a selection here:

https://www.ebay.co.uk/sch/i.html?_from ... 9&_sacat=0

So, first you need to remove the mirror shell:

Lower the glass fully.
Fold the mirror.

Mirror Shell	Using a flat tool, carefully unclip the casing (1) in the order (From 1 to 5) . Detach - Remove the mirror casing (1).

Unclip and remove: The cover (1) (Using a flat tool) . Unclip: The temperature sensor (2) from the cover (1).	Detach the sensor and the harness to obtain a sufficient length of wire. Cut the black wires of the sensor (2) (at "A"). "A" = 30 mm minimum from the sensor. Remove the sensor (2).

Refitting
Re-establish the electrical connection using welding sleeves then insulate using the heat-shrink sleeve.
Proceed in the reverse order to removal.
Check the operation.

[Sushi5734]

Thank you, that's much appreciated. It looks like something I can do by myself so I've ordered one on eBay.

[mejt1987]

is there some procedure to test them for working....i get like bit cold air, and after driving a while it blows a bit more cold air and thats it, in my audi its like 2 min after car is on, if you put on lovest seting it cuts your hand with cold on air outputs....

[GiveMeABreak]

The outside temperature sensor should be obvious if it is not working - the measurements tend to be way off if the sensor is faulty - but you can always get a cheap fridge thermometer and check the ambient outside temperature and do a quick comparison.

The Climate control systems on these are designed to reach the desired temperature gradually - but in terms of cooling, manually switching to a low temperature and putting the fans on a faster speed with the air vents at face-level should let you know if the A/C system is working ok or not - it should not take long to feel the cold air against the back of your hand. If it is taking its time and the air is cool not cold, and the temp. sensor is reading normal, then I would suspect a re-gas of the A/C system is needed.