Wonky Aircon blows hot and cold

Jeff Wray · Post by **Jeff Wray** » Sun Jan 21, 2007 7:42 pm

Hi, need help with aircon currently doing what it wants. All internal electrics failed a couple of months ago and dealer changed BSI all OK now apart from the Aircon has been all over place since.
If the temp is set to 14 degrees the air blows cool but not cold, the in car air circulation flap operates but the airflow increases slightly but will not blow fast as you might expect if you got in to a hot car in the summer. If I then change the temp to 30 degrees the system eventually blows hot air but again very slowly. When the temp is set to 21 degrees the system will not regulate the air temp it blows hot (relay hot) then cools again. I am constantly opening the windows and closing them again, the windscreen steams up unless I now have the aircon on all the time.
I have seen blogs mentioning 3no relays to control 2no fans which get badly corroded by the weather, but I think I only have 1no multispeed fan and can't find the relays. I have taken off the grille (with Pug badge) but cannot see any relays unless they are fitted in the motor housing for the fan (I don't think they would be there).
Would the polon filter being dirty effect the airflow and cause the problem or I am still to find the relays.

jameslxdt · Post by **jameslxdt** » Sun Jan 21, 2007 7:51 pm

that sounds like typical pug climate control too me

Post by **Welly** » Mon Jan 22, 2007 10:29 am

Mmmmm.

Have you had the car long?

When I first got my 406, the very first thing I asked the members here was why didn't the heater fan ramp up and down with the temperature I select (like a Jap system would).

Well it seems the Climate Control does not repond immediately, it likes to have a sit down, read the paper, go for a stroll, then and only then will is make an adjustment

Seriously though, I find it works extremelly well. In the morning it drizzles the interior with some heat, then it will ramp up a 'bit' when the engine coolant gets above 70 deg C. But it never really blasts you inside. But it is allways effective. I leave mine on 21.5 and never really touch it.

Don't forget, that at present if you select 14 deg the air outside is allready cold and so the A/C will have no noticeable affect, in fact because the cabin is cold it will actually add heat to 'make' the 14 deg so you will get the hot/cold senario.

If you are new to 406's then let it work itself, it will make sense in the end. If you are not new then we shall try and help a bit more.

jameslxdt · Post by **jameslxdt** » Mon Jan 22, 2007 7:34 pm

Welton wrote: Don't forget, that at present if you select 14 deg the air outside is allready cold and so the A/C will have no noticeable affect, in fact because the cabin is cold it will actually add heat to 'make' the 14 deg so you will get the hot/cold senario.

this is quite a common misconception, the process of air conditioning is to remove the heat from the air in the cabin, not introduce cold air into it, so if the air is already cold, air condtioning will have no effect except as a dehumidifier

Post by **Welly** » Mon Jan 22, 2007 7:51 pm

James, I know that the evaporator removes heat from the air stream. The question was why the car delivers heat when 14 deg was selected.

I was refering to today's winter weather, you cannot test your A/C at the moment as there is no load.

If the cabin was cold, and the outside air even colder, it is feasable that heat will be added to the air to achieve the 14 deg set point. Afterall 14 is a lot warmer than 2 deg C today.

This chap was wondering why when he selected 14 deg C it wasn't blasting the cabin with cold air. It simply didn't need to.

Jeff Wray · Post by **Jeff Wray** » Fri Jan 26, 2007 10:47 pm

I have had the car 3 years and never realy moved the temp from 21 degrees until the BSI was changed. When set to 21 degrees the car can be OK for 10 mins then starts to blow really hot air (without aircon on) and you therefore need to lower the temp or open the window. It never use to do this, the aircon also needs to be on all the time to keep the windscreen clear. I have cleaned out the temp sensor near the rear view mirror, the small motor runs quiet so no problem there.
Using a digital thermometer in the car, the heater seems to blow warm when it should (when it is cold) and blows cool when it gets warm inside the car, the problem is it will not regulate the temperature. It either gets too hot or too cold and the windows steam up.
Rgds Jeff

jameslxdt · Post by **jameslxdt** » Fri Jan 26, 2007 10:50 pm

take it back to pug
the BSi probably needs some new software