kskane

Hi Guys, I need help, as all air functions in my car have stopped and I don't like driving with window open and it is the summer season.

Now, I went for a drive the other day about 25degree heat, and the AC was working so fine that it got cold quickly and I had to turn off. Then the front window fogged up a little so I started the defog which was blowing strong air on the wind screen. After about 30 seconds, the defogger kind of made jerking noise and the power was reduced. I ignored that and continued driving. On my way back I realised all the following are not working any more.

1. Pressing the front screen defogger does not blows the fan to full speed on the front wind screen.
2. changing fan speed does not makes any different apart from the light moving.
3. Max button does not blow any air or cold air.
4. AC does respond physically as I can feel the engine revs fluctuate, but no cold air comes through the wents.
5. Auto function (button) has no effect to the fan speed or AC speed.

I am getting only one error code and that is 9C55. From searching the forum and the internet, I can locate this as the front defog sensor that sits under the rear view mirror.

What is puzzling me is can this small sensor for about $150 make the normal air fan speed fail? or the AC not to work completely on manual?

Apart from the sensor replacement, what else is gone that I can test. I am suspecting the blower motor or the fuse for the blower motor, but do not know where the fuse is located.

Has anyone of you had this issue in the past? Any suggestions are welcome.

westsidebalto

Have you let the car sit for a few hours and tried again? This could be just ice buildup inside.

This happened to me once. I had run the AC for a few hours on a hot summer day, parked in a very hot and humid garage for several hours, then drove again. I soon noticed that air was not coming out well and it was not very cold, similar to your symptoms. There is no real fix for this other than to let it melt.

While this isn't a hugely common E60 problem, it can happen. Some cars can have this happen frequently depending on their design (mid to late 2000s Mazda 3 for instance).

kskane

It is summer here in Australia, so temp is about 20+ and usually about 30+. Car has sat in the garrage for few nights since that would have melted anything that is cold. But thanks for the tip.

It is puzzling me how can there is only one sensor code that will take the whole fan blower motor off.