Mercedes Benz AC Blower running non-stop

**rmt6668** · March 18th, 2006 03:41 PM

My 2001 E240 W210 Air Conditoner seem to have a mind of its own it kept running non stop. I am trying to diagnose the fault. Temporarirly I have remove the 3 pin cable connected to the AC Blower Regulator.

I am trying to locate the AC Fuse? I cannot see where it is?

Is it possible that the Relay Power Contacts are welded & Sticking? Its a 1 inch Box Plug in Cube, 5 pin relay on the engine L side?

**fireblade** · March 18th, 2006 04:05 PM

I maybe wrong but when I had my 2005 Volvo S40, same thing happens. Only to find out that it is a standard feature to cool down the engine and interior when kept under the sun. goes on and off automatically to remove some humidity. Sometimes, I am already away from the car after parking and the blower is still running. Just to hear from Viking that it is standard. Could it be the same?

**rmt6668** · March 18th, 2006 09:07 PM

No, the fault is causing the AC Blower to rum 24hrs a day...on & on

I manage to open the fuse box & I see there is a hidden half of the fuse box, the RELAYS. But which is for AC? I suspect the one on top (yellow)

**Walter** · March 18th, 2006 10:02 PM

Try checking the relay also or the thermo-sensor switch.

**rmt6668** · March 20th, 2006 10:52 AM

"Try checking the relay also or the thermo-sensor switch."

Walter,

Where is the Relay? In the fuse box, there are Relays mark A to G?

Where is the thermo-sensor swicth located?

Can you post me picture? Mine is a E240 Yr2001 W210 model

Thanks again

**Walter** · March 20th, 2006 03:33 PM

Not familiar with W210s, only W124s. Had a similar problem, turns out the thermo sensor switch was replaced before, had to return to original. Then there was a problem with the fuse, relay and the resistor.

**smooth** · March 20th, 2006 06:44 PM

i don't know if this is related. i know someone who's 2002 MB S-class' A/C just suddenly switched to heater mode after he rolled down the driver's side window. we couldn't figure out what was the problem. tried everything and walang nangyari. (ang init i-maneho kasi heater ang gumagana.) the endpoint: the car was brought to the MB casa where they "re-booted" the ECU. that might be the solution to your problem. btw, this "re-booting" costs 60K or 80K (sorry can't really remember how much). how do they re-boot? they bring in this really high tech looking aluminum attache case thing, plug in some cables into the MB, push some buttons, and voila! ayus na ang kotse (and there went the 60K). fastest way of losing 60K i've ever seen (excluding betting in casinos that is).

**rmt6668** · March 20th, 2006 10:54 PM

Where is your thermo sensor swicth located?

Are you sure they can reboot the AC Control Unit?

**rmt6668** · March 21st, 2006 06:21 PM

Hi again,

I finally manage to pull the AC Control Unit off. Attached are the pics I have taken. Surprisingly with the AC Control Unit disconnected, the Blower still kept blasting away. Is it back to the Regulator or even the Thermo Sensor Switch Faulty?

Can some one pls lead me in the right direction very much appreciated.

**theveed** · March 21st, 2006 06:29 PM

Originally Posted by smooth

i don't know if this is related. i know someone who's 2002 MB S-class' A/C just suddenly switched to heater mode after he rolled down the driver's side window. we couldn't figure out what was the problem. tried everything and walang nangyari. (ang init i-maneho kasi heater ang gumagana.) the endpoint: the car was brought to the MB casa where they "re-booted" the ECU. that might be the solution to your problem. btw, this "re-booting" costs 60K or 80K (sorry can't really remember how much). how do they re-boot? they bring in this really high tech looking aluminum attache case thing, plug in some cables into the MB, push some buttons, and voila! ayus na ang kotse (and there went the 60K). fastest way of losing 60K i've ever seen (excluding betting in casinos that is).

Langhiyang raket yan ah.