Where is the Aux Fan Control Located and How Does It Get Replaced
 

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.

http://img.eautopartscatalog.com/liv...1813489STR.JPG

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?

What year and model car?

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.
:)

Bump

and thanks for the tip vstech

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

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?

Thread Hi Jack
 

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!

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

the vin ends in XA9079078xx if that helps

AUx fan controller
 

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

Aux fan ELECTRONIC controller
 

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]

'Answer own inquirys (With Help) 124.128
 

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?

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

Yeah
 

That Electronical Aux Fan controller is about a Franklin(And an 'Arf).

AND the only real problem with the original system is the AWG/MM of the Wiring.

The "resistors",archaic as they are, Last a Long time.

Thanks all.
Found by removing front headlight.

Car is home again.

Two road trips and two major $$$$ and two strandings!!!!!!!!!

The first an alternator 2,576 miles from home and stranded.

The second 2,528 miles from home and stranded by failed aux fans and control unit again major $$$$.

Are 1999 E300 Turbo Diesels only city cars and shouldn't be taken farther from home than you can afford to have them dragged back home?

I can't find the controller!! Help
 

Hello,

My first time here I am so thankful that I found this information about the Aux. Fan controll. I have a 1999 MB E300D. I have looked and looked where the above indicates, (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 I can not find the fan controller. Any chance that it is below the washer fluid jug?

None! The mechanic who did mine took the driver's headlight out and it was under the light, saw it from the waiting room, I did not go right up to the car to see it up close.

Hope this helps

You can test the aux fan operation using the CCU; with key in pos #2, hold both "auto" buttons for 10 seconds. Fans will engage full speed.

Aux. Fan?
 

Great, thanks for the location information. The problem I am having is that the fans cycle up and down in speed but never go to full speed. I jumped the wires and the fan runs great. I am assuming the fan controll is the culprit.

Thanks,
Scot

The test described above should put them to full speed. If they don't hold that speed in diagnostic mode I'd suspect the controller.

Surprised you notice them being on. Mine only cycle on when its a 100-105f day and then only after exiting the freeway and entering stop and go traffic.

That sounds normal.
What temperatures is your coolant running at?

Temp.
 

The coolant temp runs around 80 unless I get in stop and go traffic. Then it has risen over 100.

I tested the clutch on the engine fan and have a new one on order. I am also going to put in a new controller for the electric fans as they barely move even when the coolant temp has climbed above 100. Hope this will solve the high temp in traffic and warm AC in traffic.

OK Too hot. Over 100 is not good. Sounds like a good plan.

If you have diesel going to 100C that means your cooling system lost its efficiency.
I have 3 years old radiator on 1998 E300DT and I drive in California with engine fan removed. At 102F outside at 70 mph the engine stays at 78-80C. Got up to 95C in city traffic, but when left idling on parking lot, it drop down to 92C with AC at full blast. The electric fans were on slow.
I am strong believer in MB coolant and read lot of replies where guys using cheaper stuff have problems with engines getting hot.

Installed Aux. fans not coming on. 1998 E300TD
 

I just finished installing(thanks to the DIY guys) a set of used Aux. fans. They work when I use the test method with the Auto buttons. The cold air comes on when I run the air condition, but as soon as the compressor get hot it shuts down because the Aux's do not start. Now what?:confused:

96 e300d auxiliary fan control module location
 

Hi ,
The ac fan does not come on in my 96 e300d. My control module is faulty. I traced the wire/cable from the aux fan and noticed that goes into the fuse box. After that i can't see where/what it hooks up to and don't see a control module inside the fuse box. Any input is appreciated. Have a great day !

smk_texas