External Temp Sensor and Front Screen Demister

Talk about the 406's electrical system, what wires do what, how to add extra functionality, etc.

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pugface406lx
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External Temp Sensor and Front Screen Demister

Post by pugface406lx »

Hi Guys,

My 406HDI has a problem in which the External Temp sensor has been going 'wappy'....first its -10C then it slowly changes through the spectrum and goes up to 50c. then 2 dashes.....in January ???? mmmmmm I think not.
Anyhow Ive ordered a new sensor from the main stealer at £15 .......its located in the door mirror housing passenger side apparently.

My question is this........does the front screen 'fast demister' when switched on, operate in conjunction with what the reading outside is saying because its suddenly not blowing at the screen like it normally does on a really cold day like today...freezing.....it appears to lack lustre and im wondering if its interlocked with whatever the outside temp sensor is doing...ie reading says its about 48c outside so does the force of air decrease accordingly.....???

Any thoughts welcome..

cheers
Puggy
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Welly
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Re: External Temp Sensor and Front Screen Demister

Post by Welly »

Yes the climate control uses the external temp and the internal temp to determine what to do with the fan speed and it's confused.

Should be fine once you've changd the sensor - have you searchedfor a how-too as there's a few ways of doing it (cutting and soldering being the favourite).
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mjb
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Re: External Temp Sensor and Front Screen Demister

Post by mjb »

Actually I think the windscreen demist setting (at least on D8s) only cares about the coolant temperature. It doesn't start to belt the air out until the engine's up to temperature

I tend to put it on that setting, close the dashboard vents, then crank the fan up to full
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Welly
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Re: External Temp Sensor and Front Screen Demister

Post by Welly »

The D9 does full blast on this setting regardless of coolant temp but on the other modes it does indeed wait for the coolant weird eh?
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steve_earwig
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Re: External Temp Sensor and Front Screen Demister

Post by steve_earwig »

Apart from my D8 which blasts cold air at the screen just after the engine's started :? Not so nice at minus stupid.
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Doggy
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Re: External Temp Sensor and Front Screen Demister

Post by Doggy »

I think it's because D9's have additional electric heating and so have some warmth almost as soon as you start it up 8)
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pugface406lx
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Re: External Temp Sensor and Front Screen Demister

Post by pugface406lx »

hiii ...is mine a D9 ?? its a 2000 W reg. HDI 2.0 Estate 110BHP

cheers
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teamster1975
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Re: External Temp Sensor and Front Screen Demister

Post by teamster1975 »

pugface406lx wrote:hiii ...is mine a D9 ?? its a 2000 W reg. HDI 2.0 Estate 110BHP

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pugface406lx
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Re: External Temp Sensor and Front Screen Demister

Post by pugface406lx »

hi there.....thanks for the info guys its a great help.

Finally ....is it easy to get into the mirror to replace the sensor ?..how does the glass come out?....and is there any how to guides on here?...if so where as i dont see them readily advertised..?

The 406 is one of the best cars Ive bought yet...and what a great fuel economy i got 54mpg average going around dorset from the midlands on holiday last summer....it was fully loaded up to its gunnells and i still got around 730 miles on one tank...!!! wow

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averagejo
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Re: External Temp Sensor and Front Screen Demister

Post by averagejo »

only one ive come across so far is viewtopic.php?f=3&t=4616

going to take a look at mine though as it aways reads (well bar once for 5mins) '--'


dan
406 GLX D9 2001 2.0l 16v EW10J4
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averagejo
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Re: External Temp Sensor and Front Screen Demister

Post by averagejo »

Welton wrote:Yes the climate control uses the external temp and the internal temp to determine what to do with the fan speed and it's confused.

Should be fine once you've changd the sensor - have you searchedfor a how-too as there's a few ways of doing it (cutting and soldering being the favourite).
got a new sensor from pug, all sorted and works a treat :mrgreen:


dan
406 GLX D9 2001 2.0l 16v EW10J4
pugface406lx
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Re: External Temp Sensor and Front Screen Demister

Post by pugface406lx »

How do you get into the mirror without breaking too much?.....my door mirrors off the car but I cant get the glass out......ive got the colour coded panel off and broke the 2 bottom clips on that but cant get any further...scratching my head here...please help??


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averagejo
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Re: External Temp Sensor and Front Screen Demister

Post by averagejo »

all down to the haynes my friend :mrgreen:

tilt the glass as far up as you can - then a tiny bit more and just under the bottom edge of the glass you'll see the two prongs of a retaining clip, slide one towards the other then backwards to release then just lift off and watch out for the heated glass wires (dont know if its on all of them). now from memory - once its off remove the 3 torx screws and screw for the temp sensor then remove the black facia edge trim, after that hold back the clips that are holding the mirror motor in place (if its 'leccy) then slide back and twist and the whole housing should be off which should give you plenty of access to the wires. you dont need to remove the colour coded housing so glue that back on.

dan
406 GLX D9 2001 2.0l 16v EW10J4
pugface406lx
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Re: External Temp Sensor and Front Screen Demister

Post by pugface406lx »

Thanks for that, Got it off by doing what you said.

Thanks again, sensor now replaced and working ok

Regards
PUGFACE
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