1998 740il - BMW Forum

boomer1 · 09-11-2011, 01:45 AM

Just recently purchase this car. It runs great. My issue is the a/c not blowing any air, the control panel have been changed. Any suggestions would be great. thanks.

brettski · 09-11-2011, 04:26 AM

Welcome to the Werkz. Always good to have another 7er on board.

Do you mean the fans aren't blowing air at all, or not blowing cold air(AC)?
Can you hear the AC compressor engage when you turn the cooling on? Does the idle change at all when the compressor engages? If you answer no to either or both of these, you may need to get the system regassed or serviced. I am pretty sure that there is a pressure sensor which will disable the system if there is insufficent pressure.

Let us know what you observe.

boomer1 · 09-12-2011, 12:35 AM

Thanks for the warm welcome. This is my very first BMW owned. Very impressive car.
Yes, the fans aren't blowing air at all no matter what settings.
I even tried the heater to no avail.
Yes, there was a slight idle change when set to ac is set to "Auto".

brettski · 09-12-2011, 05:20 AM

Have you checked the fuse for the blowers?

boomer1 · 09-12-2011, 08:43 PM

I checked the fuses under the hood for ( air con slots 7, 11, 20 ) and its ok.
is there another fuse box that I don't know about or maybe relay's?

Jack Dabsy · 09-13-2011, 01:56 PM

Got to be the famous hedgehog resistor/rectifier attached to the blower... This controls fan speed and temps, and is a common fault !!

boomer1 · 09-13-2011, 10:17 PM

Quote:

Originally Posted by Dabsy

Got to be the famous hedgehog resistor/rectifier attached to the blower... This controls fan speed and temps, and is a common fault !!

Is it hard to replace? if you don't mind where it's located?

brettski · 09-14-2011, 05:23 AM

Have a look at Blower Motor Replacement Procedure

Jack Dabsy · 09-14-2011, 02:34 PM

Yes it is a twat to change but the results are worth it !!
It is under the footwell so some trims need to be removed and get ready to lay on your back for better access !!

boomer1 · 09-14-2011, 06:42 PM

Thanks for the link. I can now have a better view of what I am up against.

boomer1 · 09-14-2011, 06:43 PM

Quote:

Originally Posted by Dabsy

Yes it is a twat to change but the results are worth it !!
It is under the footwell so some trims need to be removed and get ready to lay on your back for better access !!

Thanks for the insite.