I must have a horse shoe stuck up my butt!......another lucky quick fix!

My Auxiliary Fan had started working intermitantly and then finally quit over this past year. Direct voltage to the Fan at the plug would occationaly get it to work if I spun or jarred it. The CCU indicated the variable current was happening when the coolent and AC system hit certain temp thresholds but the fan would not run anymore.

I remove the motorized fan from the assembly but before I bought a replacement I wanted to see the condition of the brushes and commutator.
So I tried to remove the fan from the shaft to get at the motor. I did not have a puller with long enough arms so I supported the fan on blocks of wood with the back of the motor hanging down and gave the center shaft some wacks with a hammer and a broad center punch. The fan did not budge but about an ounce of fine "road dust" fell out of the vent holes in the back of the motor. So out of curriosity I flushed the motor with electronic cleaner/ MAF cleaner and wacked it a couple more times and flushed the motor again.

I tested the fan after I temporarily screwed it back on the frame and it ran better than when I bought the W210 in 2005 on low and high 12 volt current.
Now its working great!

__________________
FRED

Daily Driver: 98 E300TD 199K
Hobby Car: 69 Austin Mini
Past Diesels: 84 300SD, 312K
87 300SDL, 251K
94 Chev. K-1500 6.5Ltr.TD, 373K

Nice job! It's great to find those free fixes!

__________________
-Evan


Benz Fleet:
1968 UNIMOG 404.114
1998 E300
2008 E63


Non-Benz Fleet:
1992 Aerostar
1993 MR2
2000 F250

You probably seated the brushes back against the ring - whether it stays fixed or not only time will tell!

__________________
Marty D.

2013 C300 4Matic
1984 BMW 733i
2013 Lincoln MKz

Yep! I am wondering how long it will last. But it was amazing at how much debris and grit was in there!

__________________
FRED

Daily Driver: 98 E300TD 199K
Hobby Car: 69 Austin Mini
Past Diesels: 84 300SD, 312K
87 300SDL, 251K
94 Chev. K-1500 6.5Ltr.TD, 373K

Had the same problem with mine but I only did the "spray with electrical cleaner" part and now mine has been working for a month, so far so good!

__________________

Muleears
'07 E320 Bluetec 133K my DD
'04 Jaguar XJ8 VDP, 34K
'10 Hyundai Accent 60K Grocery Getter
'02 VW Golf soon to be on the road again
'97 E300 Diesel Son's DD
'61 VERY tolerant wife

Hampton Roads, VA USA

Gone but not forgotten:
'67 250S 95K
'86 300SDL
'87 300D Turbo, 364K! R.I.P.
'98 E300 Turbodiesel, 213K
'02 S420, 164K
'01 Prius 138K

I have the same issue and I was able to get the fans to run after manually turning. I want to remove the fan, but from what I can tell I need to remove the radiator first. Is this the case, or am I missing something obvious and easy?

No need to disturb the radiator or AC condenser. It's a very easy 20 minute job to R&R that fan assembly.

Add another half hour or so to replace the motor and belt, if that's what you're going to do.

The new motor is about $200 (get a new belt too). DO NOT GET IT FROM EBAY! If you want a cheap Ebay replacement, I have one in the garage that I won't give away because I don't want you to damage your car.

No need to disturb the radiator or AC condenser. It's a very easy 20 minute job to R&R that fan assembly.

Add another half hour or so to replace the motor and belt, if that's what you're going to do.

The new motor is about $200 (get a new belt too). DO NOT GET IT FROM EBAY! If you want a cheap Ebay replacement, I have one in the garage that I won't give away because I don't want you to damage your car.
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Thanks for the reply on this. I got into it a bit last weekend and decided after looking at the position of the lower fasteners, I'd outsource the work. A new fan and motor were installed and quit working on the way home. The indy I used to change out the parts determined that the cause was an improper amount (too much) freon in the a/c system and the increased pressure was shutting down the compressor and, thus, the auxiliary fan. So the system was drained and refilled with the "proper" amount of freon. Everything worked well for a day. I was in the middle of a 1,200 mile week when my temp gauge started to rise above 90c while waiting to get through an ICE checkpoint. I stopped and looked at the fans and they weren't spinning. When I stopped for fuel about 400 miles later, I checked again before shutting down the engine and nothing. The temp gauge was just above 80c at that point.

Any suggestions on what or how I should troubleshoot? I'd like to identify a plausible issue before going back to the shop as I dislike returning more than once, much less twice, for the same problem. Many thanks again.

If the motor is going bad, it may sometimes refuse to start from a stop.

Run the fan test a few times. Ensure that the blades are stopped each time before you turn them on. If they ever fail to start, you need a new something - motor or controller and probably motor.I have the same issue and I was able to get the fans to run after manually turning. I want to remove the fan, but from what I can tell I need to remove the radiator first. Is this the case, or am I missing something obvious and easy?
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To enter fan test - with key in position 1 or 2, press and hold both AUTO buttons for >10 seconds, until the fan starts. To end fan test, turn key to position 0 or press and hold both AUTO buttons for another >10 seconds.

And there aren't any "lower fasteners." It sits in a pair of rubber blocks at the bottom of the radiator. The only bolts holding it in are on top. As I said, it's a very easy job.

To enter fan test - with key in position 1 or 2, press and hold both AUTO buttons for >10 seconds, until the fan starts. To end fan test, turn key to position 0 or press and hold both AUTO buttons for another >10 seconds.

And there aren't any "lower fasteners." It sits in a pair of rubber blocks at the bottom of the radiator. The only bolts holding it in are on top. As I said, it's a very easy job.[/QUOTE]

I ran the test four times and fans came on three times. The third attempt I tried while keeping the key in position 2 from the second attempt. I opened the door to make sure the blades stopped following shutdown from the second test and kept it open for the third attempt. I closed the door for the fourth, successful attempt. Would having the door open cause the fans not to come on?

No, the fans don't care if the door is open.

Try again. If you get it to fail, try to start the fans by hand. Don't let your hand get into the blades, in case it starts up.

If you can get it to fail, then start by hand, most likely you need a new motor.