Hallo,
Ich bin von England aber hat ein Problem, dem niemand scheint, auf englischem T4 Forum beantworten zu können.
Ich habe retro hat gepasst einem mfa tacho und auch installierten äußeres Temperaturmessgerät, das auf dem mfa zeigt.
Obwohl wenn ich den Zeitarbeiter treibe, behält, ich zu steigen, habe verschiedene Orte versucht aber bin gesteckt!!!
HILFE
If you write in English, it's easier to understand your problem 
Sorry, just trying not to assume that everybody speaks English. As I do not speak much German as you can probably tell!!
Anyway, I have a problem with my retro fitted MFA ooutside temperature, it seems to be fine when still but when you drive the temperature rises and rises.
I have tried different locations in and around engine bay but no luck. any ideas???
HELP
the wiring is ok?
the location for the sensor is behind the bumper
there the engine has no influece
how much is the difference between the temperature when you start the engine and the maximum temperature?
Yeah put it behind the bumper where is recommended.
Yes sure wiring is all in correct place, as wiring was already present to centralelectric, and just had to wire additional kufatec wiring harness to purple wire in green connector of instrument cluster (not sure this is even required although seems to make no difference if there or not!)
The temoerature is ok while stand still but when you drive along it goes up and up! Stops around 35 C whatever the actual temperature outside, although it doesn't reach that in England ever!!!
I think the sensor for the MFA and the climatronic is the same
do you have climatronic??
have you testet your system with another sensor
perhaps your sensor is damaged in some way
Where exactly have you installed the Sensor? I retrofitted MFA instruments also and installed the Sensor in the front bumper under the number plate, which doesn't seem to be the perfect location. Depending on the outside temperature, the shown temperature seems to be higher than the real outside air temperature. (About 2-6°C error)
You can see my sensor here: Direktanschluß MFA-Hebel an Tacho mit FIS
I do not have climatronic in my caravelle though do have air con which strangely when turned on makes the temperature rise quicker!!
I have not tried another sesnsor yet maybe my next plan.
I have tried my sensor behind the front bumper near my spotlights and in various other positions along the front bumper. Not sure whether it needs to be where the air flow can get into it???
How did you guys wire yours into the mfa or was the wiring already there?
when you turn on your air condition the temperature in your mfa rises quicker?? 
Yes very strange!!! 
Will still rise if off but doesn't seem as quick.
Seems to get up to 35 C whatever the temperature outside and then doesn't go higher!
It does seem to start at the right temperature though I think!
test another sensor then we'll see
and check your sensor with an multimeter to prove the resistance
Temperatur [°C] Resistance [Ohm]
5 2800
10 2400
15 2000
20 1600
25 1200
I have tried to get hold of another couple of sensors so will let you know ehn these turn up what happens.
ensure you get your sensor
i think there are two different sensors for the T4
otherwise your sensor does not rise but monitors still a false temperature
