[allsprings]

Here's what happened:

I am driving along all good. The next time I started my car the air condition was really loud. Not a knocking sound, or a wincing sound, but it is just a loud air-moving sound. instead of sounding like a car AC is sounds like my house furnace air intake !! Any ideas ?

 

[Cornishman]

Perhaps the blend motor or motors have failed and the air is only coming out of one bank of vents, instead of being distributed around the vehicle?

 

[Jos Geuze]

Hi

Is your climate control unit on AUTO ?

Switch it to manual and see if the fan rotary switch and bar in the LCD display are in line with the air output through your vents into the car.

Are both fans running or has one fan stopped and the other one is turning full blast? The fans supply air into a common duct and when one of the fans stops working the air of the working fan finds the easy way out which is through the not working fan. This is easily checked by switching to recirculation and checking under the dash in the footwells. The fan inlet there that lets out air is the fan that has stopped working. Check fuses and wiring. See the main site and on this forum several posts have been dedicated to the problems of the fans not working.

Good luck

Jos

 

[allsprings]

1. the air moves through all the vents. when i switch to get the air out the footwell, or along the windshield, or right at me the airflow changes to the correct one every time. and it uses all the vents, left and right.

2. my climate control is NOT on auto. in fact, the fan is turned all the way down yet the air output is acting as if it were on HIGH.

 

[Jos Geuze]

Hi

The fan speed is controlled by the ECU. It will supply a certain voltage towards the speed regulation circuit at the negative side of the blower motor. The positive side gets its supply from the +12VDC via the relays. Depending on the voltage signal towards the blowers from the ECU the voltage over the blower motor is small when the voltage from the ECU is high and rises with the ECU voltage becoming lower until the line from the ECU is grounded which will achieve maximum blower speed.

When the fan is blowing all the time at full speed something can be wrong in the wiring causing a leak to earth, or there is a component failure in the ECU causing the earth path inside the ECU. Faultcodes are logged and stored in the ECU.

The fan speed from the Dial is bypassed when the demister program is working and when the system is in AUTO mode.

Regards

Jos

 

[david despain]

allsprings, any update?

 

[allsprings]

well here is the update.

fan is always on HIGH, when i hit the 'AC Off' button, it quiets down a little, but fan still blows high.

1) i checked all the fuses these is no problem there.
2) jos's description of the problem is too technical for me and to be honest i don't really know how to 'check the earths'
3) i found a potential solution here but i am not sure if i have the technical expertise to perform the operation:
viewtopic.php?f=3&t=32538&p=251621&hilit=fan+high+only#p251621

you got any ideas ?

 

[david despain]

ideas? yeah i was planning to do the same as the link you posted, replace the transistors. i had my RH blower and torn down to that point a few weeks ago and had hoped that cleaning the brushes and cleaning the gunk off of the transistor/relay assembly would help. it didn't. my local hardware store has a pretty good assorment of brushes too so i will probably try to find a correct size replacement and renew them at the same time.