124 aux fan replacement - PeachParts Mercedes-Benz Forum

Stoney3 · #1 05-14-2004, 01:48 PM

I need help replacing a aux fan on a 1993 300E.

#2 05-14-2004, 04:01 PM

What kind of help do you need? Is it a single fan or a dual fan system?

Good luck,

Stoney3 · #3 05-14-2004, 04:24 PM

It's a 2 fan system. The 124 cd talks about disconnecting the a/c lines and removing the radiator. There has to be an easier way. I hope.

wjm · #4 05-14-2004, 07:02 PM

Hoping on a reply as well. I have same question posted here:

http://www.peachparts.com/shopforum/showthread.php?threadid=94206

Why do you think they need replacing? Mine seem to be acting strangly. Sometimes the right goes out... sometimes it's the left. My mechanic thinks they are fine and that the problem might be elsewhere... possibly the replays. It's almost like there is not enough power to get both of them started. Once they're both moving, they seem to stay on fine. It's once they stop that seems to be the problem.

BamaMB · #5 05-14-2004, 08:18 PM

It can be done without disconnecting the A/C condenser lines but you will have to move the condenser. I did it on me 1900 300e. Had to remove the radiator, move the condeser back a bit, remove the frame member in front of the two fans. A pain in the knuckles, but can be done.

Stoney3 · #6 05-14-2004, 09:31 PM

wjm, The left one dosen't work periodically unless you tap it. I think the brushes are going bad.

Stoney3 · #7 05-14-2004, 09:36 PM

Thanks BamaMB. Iguess I should have replaced it when I replaced the water pump.

wjm · #8 05-14-2004, 09:44 PM

Stoney,

Sometimes it's the left... sometimes it's the right. Although the brushes are a very probable cause, I find it a bit strange that BOTH would act up at identical times. Almost like not enough power to get both fans started at the same time.

Arthur Dalton · #9 05-14-2004, 10:33 PM

Quote:

Originally posted by wjm
Stoney,

Sometimes it's the left... sometimes it's the right. Although the brushes are a very probable cause, I find it a bit strange that BOTH would act up at identical times. Almost like not enough power to get both fans started at the same time.

If a bad connection is suspect [ low power], the place to check is the common connector side of the speed dropping resistor behind the left headlamp.
This is a common burn/corrosion spot and can create a poor connection . This will be the feed side of the resistor that has two wires connnected. The single wire connection side is the feed for low fan [ A/C activated.]

wjm · #10 05-15-2004, 04:37 AM

Thanks.

A couple of year back, I replaced the resistor and cleaned up the wiring, as one had coroded off.

I'll check it again anyway.

Robert W. Roe · #11 07-18-2004, 03:09 AM

Hmmmm, my shop quoted me $120 to replace the fans.
It's tempting to let them do it ... does $120 sound reasonable, or too good to be true?
I guess they could remove the radiator a lot faster than I could.
I wonder if the fans could be removed from the front?
My 1991 300TE has a couple horns and some metal tubing in front of the aux fan assembly.

wjm · #12 07-18-2004, 09:53 AM

$120... that obviously does not include parts, right?

AEL · #13 07-18-2004, 11:25 AM

There are many of us out there who would appreciate a detailed description, with photos if possible, of the replacement without disconnecting the a/c or any other major hoses. It looks tauntingly doable from the front of the radiator. Someone said he removed his front bumper to gain access to the fans. However, I believe that was on a 190. Prices of the fan have gone well north of $100. since the drop in the dollar.

wjm · #14 07-18-2004, 11:40 AM

I'm sitting on 2 fans myself ready for install.

This is the article I found for replacement. I have not read through it carefully, so any comments would be appreciated!

Quote:

Aux Fan Removal and Installation
By Neil Chandler, Sunday, July 6, 2003

A week ago I requested help on how to remove the auxiliary fans on a Model W124 E420. Thanks to the this wonderful list, and the people who are members, within hours I received four replies. I would like to publicly thank Richard McGinnis, Mike Yox, Kevin Kenner, and Marshalll Booth. The instructions worked just as described, and I have replaced the faulty fan. There are a few variations an E420, so I thought that I would describe them.

-Before you start, buy some new plastic rivets for the fan housing. P/N 123-990-00-92, 70 cents each at the dealer. The fan P/N is 000-500-85-93, $138 from Caliber.

-Remove the bumper, which is held on by 7 bolts, all visible and easy to reach. This lets you see everything, and avoids working below the car. You will also have to remove the license tag, and the carrier which holds it. In my case, I found that the carrier fits onto a metal strip, which was badly rusted, and needed replacing anyway. Remove the clip that holds the outside temperature indicator sensor in place, and poke it back into the bumper through the large hole. For a big piece, the bumper is surprisingly light and easy to handle. One person can do it easily.

-Remove the right head-lamp if you have to remove the right fan. (No need if it is the left fan). The two 8mm bolts which hold the outside edge of the right fan are almost impossible to start unless you can get at them. The head-lamp cannot be removed until you first remove the associated indicator assembly, released by a spring clip inside the black plastic air duct on the back of the head-lamp. The metal trim rail immediately below the lamp is secured with an 8mm bolt at each end. If you have head-lamp wipers, remove the arm, but leave it hanging on the water supply tube. Remove two more 8mm bolts visible inside the indicator housing, the upper clip (turn it 90 degrees), and the inner 8mm screw, next to the condenser, and the head-lamp can be wiggled out. If the wiper motor gets stuck, slide the rubber cover up the shaft, and loosen the 17mm nut holding the motor to the bottom of the lamp assembly. It will come out and go back in all in one piece.

-As Richard said, remove all 6 spring clips that hold the fan shroud, radiator, and condenser in place, and push them all back gently against the thermo-clutch. NB - Put a piece of cardboard between the fan and the radiator.

-Remove the horns and unplug them, and remove the reusable tie-wrap that holds the loom to the brace..

- Working in between the condenser and below the upper chassis cross-brace, using an offset ring wrench, remove the bolt which holds the top of the brace. There is not enough room to use a ratchet. Remove the bolt on the front of the upper chassis rail which also holds the power steering cooling loop.Remove the bolt that secures the bottom of the cooling loop to the body. Remove the screw holding the cooling loop to the chassis, behind the left head-lamp. This allows the loop to move a little more.Working from behind the bumper frame, remove the bolt that holds the bottom of the brace, and lift out the brace.

- Remove the air-tube to the left head-lamp air duct, unplug the sensor, and lift out the duct. (Do not forget to reinstall the sensor before you start the engine to test, because if you leave it off, it will set the red engine trouble light).

-On top of the chassis rail behind the head-lamp, you will see a clip holding the male and female plug for the power supply to the fans. Pull off the clip, and separate the two halves of the plug. Remove the tie-wrap holding the end of the fan loom. (If you did not already do so, this is the time to function-test the fans, but use a direct line to a battery, as the fans draw a lot of current.)

-The fans are bolted onto the condenser, and are covered by a plastic molding. The molding is held in place with 6 plastic rivets. There are four across the top, easily visible and accessible, but the lower two are only reachable from below. The center pins may be brittle and break off in place. In this case, just push them inward, through the rivet, and then remove the outer part of the rivet.

- Remove the fan molding. This takes a lot of pulling and pushing, but the molding is flexible, and comes out upwards.(When it is re-installed, there are three lugs which fit into the condenser, which are only visible when the bumper has been removed)

-The fan power harness is actually two separate cables inside one sheath. Each fan has a power lead coming off it, which is held on a bracket attached to each fan. The harness ends in two female two pin plugs, with side clips which must be depressed to separate the plug assembly. If you want to test or repair the harness, there are two clips securing it to the condenser, but there is no need to remove them otherwise. It is not easy to remove them without breaking them. Unplug the plugs, at which point you can also test each fan one by one if you want. Be sure to securely reseat the plugs when replacing them. It is a lot of work to fix a loose plug!

-The fans are held to the condenser brackets with a total of 6 ea 8mm bolts. As Richard said, the upper right and the lower left, on the outer edges, are bolts with a loose nut (which is hard to find if you let it drop by mistake!). The other four are all threaded directly into the fan outer housing ring.. The outside 4 are all visible, but very difficult to get at, as there is only1/2 inch of clearance. A ratcheting gear-wrench is the ideal tool for this. The two center bolts can be reached through one of the larger gaps in the fan blades, using a 1/4 inch ratchet. If you only want to remove one of the fans, leave the outside bolts in place for the fan to be left in place.

-Remove the fans upwards, wiggling the loop as you do so.

-Remove the clip which holds the wiring plug from the old fan, and re-use on the new fan.

-I found that the most difficult thing to do was to start the 8 mm bolts on the outer edge of the fans, simply because there is no access to get at them.

-Clean out the space between the radiator and the condenser, and at the bottom of the front of the condenser.

-When you replace the bumper, be sure to re-align the ventilation ducts and the upper rubber moldings, and don't forget to run the temperature sensor back through the hole first. Replace the right head-lamp.

-Test the fan functionality with a separate power supply at the main harness plug, then reinstall the head-lamp duct and back cover, and air tube, with the air temperature sensor put back in place.

Robert W. Roe · #15 07-18-2004, 01:14 PM

WJM, thanks!
It's very good to have a detailed description like that prior to working on one's car, especially when one (me) is not an expert at disassembling W124 front ends

I spent the better part of a weekend putting 500E Hella euro headlamps on my car; most of it was spent getting one little 8 mm bolt into the inside right headlamp grrrrrr... I just bought a Sears Craftsman ratcheting 8 mm wrench for "next time"...

To answer your question, no, the $120 is labor only.
My shop had quoted me $350+ for the aux fan assembly; via ebay I've been able to find two used fans for a total cost of around $125.
Having read the procedure, I will definitely give test each fan with 12 VDC to see if they spin prior to doing anything.
My wife has said that $120 is about what my time for a day is worth (to her), so it's a bit of a toss-up as to whether I, or Star Service Center in Allentown will be putting these fans on my car.