Climate control question

rayc · Unread post by **rayc** » 22 Apr 2006, 21:35

On my 1999 Mk2 406 hdi Executive I have the A/c on all the time and the fan on auto.

My question is:-

the fan in auto mode boosts occasionally . ie when you turn the heat up full and the cars been running a while.
However, in the sun and with the temp set to 16 (outside may be 16 also but in the car probably 30) the a/c blows cold but the auto fan doesn't pick up its speed.

Does the a/c have a temp snsor in the car to control the fan or is it linked to the external one (I know that sounds daft). I know there is a sensor on the centre of the dash. Do these control the fan and do they go wrong / insensitive.

I am in your hands again chaps!

Thanks in advance

Ray

fastandfurryous · Unread post by **fastandfurryous** » 22 Apr 2006, 21:39

The auto fan system measures the difference between the interior temperature, and the requested temperature, and blows harder the more difference there is, so if you've requested 16 and it's been sitting in the sun, it will blow A/C hard. Likewise if you've requested 26 and it's winter, it will blow hard (but ONLY once the heater matrix is hot... clever eh?)

If the temperature is fairly similar to what you've requested, then the fan "backs off" to a low speed.

It sounds like the A/C in your car is directly chilling the sensor, and thus the fan is slowing down too soon.

There's a teeny-tiny little fan in the interior sensor... which can fail. Does yours work?

rayc · Unread post by **rayc** » 23 Apr 2006, 09:06

Thanks for that info.

The function now makes sense.

Where is the sensor located?

On my old BMW there was a grid in the front of the control panel which was the A/C sensor. However I cant see this on the Peugeot.

Thanks in advance

Ray

meonk · Unread post by **meonk** » 23 Apr 2006, 17:36

its next to the map reading light..... i think...

rayc · Unread post by **rayc** » 25 Apr 2006, 13:45

Found it!

Exactly where you said in the overhead console.

The fan etc was working so I sprayed it with electrical contact cleaner (Seems to be a wire going across).

Went out in the car this morning and the fan boosted a treat (Just hope it keep's doing it!)

Another little niggly job jobbed thanks to you guys!