Where is the Aux Fan Control Located and How Does It Get Replaced - PeachParts Mercedes-Benz Forum

EDBSO · #1 05-12-2012, 12:07 AM

No longer stranded in Las Vegas ...The guys at Las Vegas Auto Repair Mercedes Repair | Porsche Repair | Volkswagen Repair | AutoBahn Benz Auto Service have the fans installed but they can't find the location of the Auxiliary Fan Control Unit.

I am now in Moab, UT using a jumper wire from the battery to provide cooling as necessary.

Where is this part located and how do I replace it? Thanks

PS their tests determined mine was toast, any tests I can do to confirm this, other than the fans only work with a direct jump from battery?

ROLLGUY · #2 05-12-2012, 12:46 AM

What year and model car?

EDBSO · #3 05-12-2012, 01:05 AM

Quote:

Originally Posted by ROLLGUY

What year and model car?

really????1999 Mercedes E300TD daily driver

vstech · #4 05-12-2012, 07:26 AM

Quote:

Originally Posted by EDBSO

really????1999 Mercedes E300TD daily driver

many members have their settings to block signature lines. it's always best to place the problem vehicle description in the first line of the original post.

EDBSO · #5 05-12-2012, 05:55 PM

Bump

and thanks for the tip vstech

EDBSO · #6 05-13-2012, 12:35 PM

BUMP

daddi · #7 05-13-2012, 04:18 PM

I'ts behind the front bumper in front of the left front tire.

EDBSO · #8 05-13-2012, 04:35 PM

Thanks.

Would it be accessible from the below through the belly pans,or
from inside the wheel well by removing the liner, or
by removing the headlight or yet another way?

compress ignite · #9 05-13-2012, 08:54 PM

VStech,

Is EDBSO's Aux Fan Controller/Resistor (on the '99 300TD) the updated generation of the "Heat Sink" type used on the OM601,602 and 603 s ???

If so It's a Quantum Leap forward into 1980's electronic technology VS the "Carbon lead Pile" "Battery Load Tester Type" that
graced the earlier OM60X.XXX series chassis.

I wonder if the OM606 s ALSO have an updated version of the Blower Fan's Controller/Resistor
(That may be "McGuivered" into the Earlier HVAC blower system ???)

Thanks!

engatwork · #10 05-13-2012, 09:44 PM

My 95 E300 606 engined car is running the resistor shown in pic #2 that you have attached.

EDBSO · #11 05-13-2012, 09:46 PM

the vin ends in XA9079078xx if that helps

Jeremy5848 · #12 05-13-2012, 09:49 PM

Quote:

Originally Posted by compress ignite

VStech,

Is EDBSO's Aux Fan Controller/Resistor (on the '99 300TD) the updated generation of the "Heat Sink" type used on the OM601,602 and 603 s ???

If so It's a Quantum Leap forward into 1980's electronic technology VS the "Carbon lead Pile" "Battery Load Tester Type" that
graced the earlier OM60X.XXX series chassis.

I wonder if the OM606 s ALSO have an updated version of the Blower Fan's Controller/Resistor
(That may be "McGuivered" into the Earlier HVAC blower system ???)

Thanks!

The 1995 E300D (OM606NA, W124) has the resistor that's in your second picture; older 124s have an earlier version of the same resistor.

The 1996-97 E300D (OM606NA, W210) uses a generic "pulse module" that lives in the fuse/relay box, left side of the engine bay near the brake booster. It does not use the big resistor.

The 1998-99 E300D (OM606 Turbo, W210) uses an electronic controller for the aux fan. The electronic controller, one of two types depending on year/model, is located in essentially the same place as the old-style resistor: inside the left wheelhouse, just behind the left headlight. You get to it from inside the engine compartment. Pretend you're going to change a headlamp bulb but look just behind the headlight and ahead of the ABS pump.

Jeremy

compress ignite · #13 05-14-2012, 12:41 AM

EDBSO,

Jeremy's located the device for you:
"The 1998-99 E300D (OM606 Turbo, W210) uses an electronic controller for the aux fan. The electronic controller, one of two types depending on year/model, is located in essentially the same place as the old-style resistor: inside the left wheelhouse, just behind the left headlight. You get to it from inside the engine compartment. Pretend you're going to change a headlamp bulb but look just behind the headlight and ahead of the ABS pump."

AND on the First picture YOU provided is a detail of the electrical connectors
on the controller and what they connect to inside the "lil" Aluminum Box.
[Almost like the detail provided on some Bosch type relays]
I'll bet with a DMM and a few electrical connectors and a 12Volt power source
the E.C. can be tested.(Outside the Chassis)

[This "Test" procedure description I'll leave to the Experts Like Jeremy,Arthur Dalton,
James Dean or VSTECH]

compress ignite · #14 05-14-2012, 01:04 AM

1.To use the Newer Versions of the HVAC Blower Fan Controller you'd have to
ALSO get a New: Mounting,Blower Motor and CCU.[So that's out the Door]

2.I suspect substantial Re-Wiring of the Auxiliary Fan Circuits would have to be
done to utilize the Newer ELECTRONIC controller on the Older System.
(Which uses Two different relay paths and the Dinosaur Resistor to power the fans.)

What got me started was seeing a Volvo ELECTRONIC controller used to Power
Ford Taurus Fan (Which has the highest CFM rating on Earth).

Hmmmmm. If an Electronic Controller eliminates the "Heat Resistor Drag" put on
the electrical supply system, mayhaps the Alterations would be an improvement?

Jeremy5848 · #15 05-14-2012, 01:16 AM

Quote:

Originally Posted by compress ignite

EDBSO,

Jeremy's located the device for you:
"The 1998-99 E300D (OM606 Turbo, W210) uses an electronic controller for the aux fan. The electronic controller, one of two types depending on year/model, is located in essentially the same place as the old-style resistor: inside the left wheelhouse, just behind the left headlight. You get to it from inside the engine compartment. Pretend you're going to change a headlamp bulb but look just behind the headlight and ahead of the ABS pump."

AND on the First picture YOU provided is a detail of the electrical connectors
on the controller and what they connect to inside the "lil" Aluminum Box.
[Almost like the detail provided on some Bosch type relays]
I'll bet with a DMM and a few electrical connectors and a 12Volt power source
the E.C. can be tested.(Outside the Chassis)

[This "Test" procedure description I'll leave to the Experts Like Jeremy,Arthur Dalton,
James Dean or VSTECH]

The aux fan electronic speed controller compared to the old relay-and-resistor method reminds me of the difference between the W124 heater blower controller compared to the older W123 blower controller, which uses a pack of resistors mounted on the right inner fender. Upgrading the W124 controller to the W210 style would be a lot of work and probably not worth it.

Mercedes probably has a test gadget for the controller but it's likely to be too expensive for the typical Benz DIYer and may be part of a larger test instrument. I wonder how much the aux fan controller costs? More than two relays and a resistor I'll bet!

Jeremy