A/C dash blower kept running non-stop-2001 E240
 

Hi,

Can any 1 help me. My A/C kept running non-stop even if I have turn the engine off (key removed). I have unplug power cable to the fan unit beneath the passenger seat dash. Previously the A/C wont even function/response.

Kind Regards,


RMT6668

Do you mean the blower runs all of the time??

Electronic blower regulator will cause that problem.

Hi,

Yes the Blower continues to run non-stop even with the engine turn off. Is the Regulator repairable? or need to buy new one?

Some 1 message me that for the Regulator, I can short test it by simply pushing some sepcific buttons on the AC but he cannot remember which buttons. Can any 1 please help?


Kind Regards,


RMT6668

Blower regulator on that car should be MB part number 210-821-15-51....
Mounts directly on the blower motor.

Blower Stays On
 

1984 300d Turbo 137k
Tap The Relay, The Contacts Are Sticking, Had This Happen On A 1984 Olds Went To Auto Zone $10.00 Unplug And Install Was Near Blower Motor 5 Min Done

M.B. Doc,

The Blower Regulator in front of me, the part number I read is BEHR (with Merc logo) is 210 820 62 10. Is this an original part or generic (E240 2001 W210)


RAYMOND485,

Can you please tell me where the relays are? Also where is the AC Fuse located?

Hi,

Thanks. But how do I tap the relay (where & How?) Please help me.

Also the Regulator part number is not the one you specify, its BEHR (with Merc logo) is 210 820 62 10 instead.

I want to confirm when I say Blower, its the the Blower in the car engine but the Air Conditioner Blower, which is located beneath the Passenger seat dash.

Hi,

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)

If its a faulty control unit & I bought the car new in Aug'2001, do you think it will still be under warranty?

I will be ashame for Merc to have such a bad quality. If its warranted I will not take the part apart

Blower Run When Ign Off
 

1984 300d Turbo
A Light Tap On Top Of The Relay When Ign Key Off, You Will Hear The
Blower Stop, It Will Be A Square Relay 5 Pin Ice Cube Relay Call ************************ For Catalog With Pictures 1-800-243-1220 They Need Your Make And Model

I have remove Fuse no. 4 & 7 for the Air Conditioner but the AC Blower continue blasting away. Does this conclude its the AC Control Unit Faulty & not the Regulator ?

Blower A/c
 

1984 300d Turbo
Some Of The Relays For The 300d Are The Same A/c Compressor Clutch And Electric Fan For Radiator Next To Each Other On The Left Engine You May Find This In Your Auto. Or Just Tap Each Relay On Top If The Blower Stops You Have Found The Sticking Relay, It Will Be 1x1x1 Inch Cube Relay May Be $25.00
GO TO *************** FOR BLOWER REGULATOR $147.00 FIRST PULL THE REGULATOR OUT, ITS ON TOP OFTHE BLOWER MOTOR IF MOTOR STOPS REPLACE THE REGULATOR IT A FLAT MAY BE 2 IN
PLUG IN THEIR IS A PIICTURE AT THE *************** SITE

Raymond485,

2 postings had inform me, there is no relays on the E240 Yr2001 W210 model. I have found all the relays beside the Fuse Box. There are 5 of them. I had removed all the Relays, to see if the Blower will cut off. But it kept blowing away. I even tried removing the number 4 & 7 Fuse for the Air Conditioning. It still kelp blowing. Thr postings also inform me, if the fuse to the Control Unit is remove & AC Blower still runs, it means the Control UNit is faulty.

Can you please post me, where you think the AC Relays are located. A picture will be very much appreciated.

Where is the thermo sensor swicth?

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.

Wondering why removing Fuse no 4 & 7 The Blower kept blowing?

I will put the switch or control unit back in the front dash. However I notice there 2 white plastic (pencil like) which need to be inserted into the 2 plastic behind the dash. What procedure do I look for, in putting the swicth back?

Hi,

I finally put the AC Control Unit back in the dash. I have tested the 3 pin wires using a Multimeter.

(1) Test the middle pin with AC switch disconnected--->0 Volts & plugging the 3 pin wire to the Blower turn ON full blast
(2) Test the middle pin with AC Switch connected ----->12 Volts & plugging the 3 pin wire to the Blower turn ON full blast
(3) Test the middle pin with AC switch connected (a) Switch 1---> 11 Volts (b) Switch 2--->10 Volts (c) Switch 3--->9 Volts (d) Switch 4--->8 Volts (e) Switch 5--->5.5 Volts
(4) With Engine On, test the middle pin with AC switch connected (a) Switch 1---> 12.5 Volts (b) Switch 2--->12 Volts (c) Switch 3--->11 Volts (d) Switch 4--->10 Volts (e) Switch 5--->7 Volts

Whats odd is that the Blower keep blasting away with or without the AC Switch connected or disconnected.

But the Multimeter detected 12 Volts in the middle pin when the AC Swicth is connected but 0 Volts when discoonected?

This motor is controlled by a three legged relay made out of silicon, it is doped with some chemicals and then labled "blower motor regulator" AKA: Power Transistor

ok, so the relays are in fact now the Regulator.

From the result of my test using a multimeter are you suggesting its the Blower Regulator, the most likely culpril?

Like MB DOC said way back when, the blower regulator is it's own solid state
control unit that can fail. It will run away on it's own when it fails.
It is powered directly via a 16mm circut 30 power wire with a 200 amp crash fuse. The distribution block (X4) that it connects to is under the driver's carpet below the gas pedal on a left hand drive car.
If you want to stop it from running, unplug the regulator at the blower fan.
Disconnecting it upstream will kill your igntion switch and traction control
power supplies as well.
The stepped voltage from the head unit it the control voltage for the
regualtor to dictate needed fan speed.
Your voltages are right in spec. You 99% need a new blower regulator
unit.
Regards,
DR.D

DR.DIESEL,

Thank you very much. I'm glad the diagnoses is pointing to Regulator rather than the AC Control Unit. But before concluding, out of curiousity, can I ask a few more questions:-

(1) When testing the middle pin, why is the voltage increasing as the switch reduce from 5 to 0. Some 1 suggest as the swicth increases, so should the voltage?

(2) Can you recommend a www site to purchase at a reasonable price?

Kind regards

Yes
 

http://catalog.peachparts.com/

Note:
I edited your title to include "dash blower".

Whunter,

Yes to which question please?

your problem is the regulator, most time they get wet, due to rain water or run car through car wash,take it out and dry it well, but you need to check for water leak inside the car, is the floor matt wet passenger side?

Answer:
 

-------------------------------------------------
Quote:
Originally Posted by rmt6668
Can you recommend a www site to purchase at a reasonable price?

Yes...

http://catalog.peachparts.com/

Please help ! Somebody out there !
Mercedes Benz 380 SE 1984 model, Automatic Transmission
Problem : in cooling mode heat is being blown from the dash board and cool air is coming from cooling vents. I replaced a new Mono Valve and removed CCU opened it , found no visible problem with CCU and reinstalled it . The problem remains the same.

380 SE , 84 how to reach blowe fan in the dah