306 aircon

jameshughes · Unread post by **jameshughes** » 24 Sep 2004, 14:01

I have a 98 1.8xs estate which has the auto aircon features.
When I turn the ignition on (engine not running) with the heater dials out of any auto position I can hear a constant motor like noise from behind the glove box- this does not seem to be the main blower motor.
Also the aircon doesnt work on this car- the green light will come on when manualy pressing the aircon button and will come on automaticaly when window demist is selected.
I cant hear any compresser clutch noises when i press the button.
Does this aircon have safety switches that stop the clutch from engaging if the system pressures are wrong?
Also I cant find a sight glass to check what the refrigerant is doing.
Any shared knowledge on this system would be useful before I take it somewhere for a "professional" to empty my wallet. Thanks in advance.

r_306_XSi · Unread post by **r_306_XSi** » 24 Sep 2004, 18:20

Hi There!
I too had the same Aircon problems you are describing - there is indeed a pressure switch on the system that cuts out the compressor when the pressure is to low.
There is a thread on this forum somewhere started by me that has the method for temprarily bypassing the switch to make sure the compressor still works - do a search!

jameshughes · Unread post by **jameshughes** » 24 Sep 2004, 19:56

Thanks I have done a search and pulled out the diagnosis info. I will have a go at it tomorrow.
Would still like to know what
"When I turn the ignition on (engine not running) with the heater dials out of any auto position I can hear a constant motor like noise from behind the glove box- this does not seem to be the main blower motor."
Is all about though.

PowerLee · Unread post by **PowerLee** » 25 Sep 2004, 00:15

Hi
That motor you can hear running is the small fan in the cabin temperature sensor.
Stick your ear next to its vent & you will hear it whiring away.
Just pop the vent off, suck the dust out & a little spray of wd40 or similar.
Its nothing to worry about.

jameshughes · Unread post by **jameshughes** » 27 Sep 2004, 13:53

I jumpered pins 1+2 from the aircon low pressure plug and everything starts running apart from cold air. so its a trip to get it regassed.Hopefully the fun will stop there.
I visualy checked the fan noise and it seems it is actually the main blower that spins all the time(at a very low speed) even with the fan switch in the off position.Is this normal for 306's with aircon?

PowerLee · Unread post by **PowerLee** » 27 Sep 2004, 17:59

Yes
The blower fan never stops spinning untill the ignitions turned off.
Its to keep air flowing through the car, Its normal.

jameshughes · Unread post by **jameshughes** » 27 Sep 2004, 21:15

Ok thanks for that