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

__________________
MERCEDES Benz Master Guild Technician (6 TIMES)
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MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
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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)

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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

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 -
Shop Foreman
Master Guild Mercedes-Benz Technician.

Think the dealer is expensive? Do you know how much it costs to train a dealer tech? Or buy the required MB special tools to have on hand?

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

http://catalog.peachparts.com/

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