well the fun never seems to stop with this car, this is my latest ordeal. Yesterday while driving around town, the temp got up to about 90c, and i thought "i should hear the electric fan by now"(it had been making alot of noise, clunks etc for a while, i'ts been on the way out) so i pulled over, and sure enough, the fuse had blown. I put a new one in, heard it roar to life, and proceeded. Then today, the same deal, sitting at a traffic light, and with the a/c on the fan should be on. Nothing. checked the fuse, it was blown again. This time i got smart and decided to take a look at the fan, and sure enough, and one point in it's revolution i can barely move it with my hand!! These fans are really expensive, so i'm looking at alternatives. I know pepboys, autozone etc sell electric fans, and i even found a dual one for like 50 bucks. Could i retrofit a dual electric fan onto the front and have it work just as well as the original? What about used fans? is there any way to test them before you buy another bad one like yours? thanks for your help
Ryan

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83 300SD.......sold
96 integra SE....sold
99 a4 quattro....sold
2001 IS300.......sold
2002 330i.........current.
2004 highlander limited....current.

If your sure it is " toast " .... then why not take it apart and see what is causing the binding ... some of the best times of my life have been taking apart machines which I could justify not having to put back together ...

Most electric motors are very simple things... if you are careful taking it apart you very well might just replace a bushing ( a bearing made of porous solid material as compared to a roller bearing ).

Or, if you look at it and the windings look ok,,,like not charred...then you might seek out an electrical motor repare place..... go as commercial as you can.. a big place that handles lots of motors.... take it to a couple and get their advise... they will be able to say something after using a volt/ohm meter on it... as to the condition of the windings... and it may be a simple deal to replace the bushing....

It is also very possible you can convert to other electric fans...

Check your local library for books on repairing electric motors before you start... and take pics for the FAQ pages.... Greg

thanks for the speedy reply. I too, thought of taking it to a motor repair place, and called two, both of which would not touch it with a 10 foot pole. They said those blasted things are all metric and we can't get parts for them. I may take it apart, i remember trying to last summer and stopping because it was still halfway working at the time, so maybe now is the time to see what i can fix by tearing into it. It's gonna be a hot week with no a/c.....
Ryan

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83 300SD.......sold
96 integra SE....sold
99 a4 quattro....sold
2001 IS300.......sold
2002 330i.........current.
2004 highlander limited....current.

First , do you have one of those new 9 bladed fans on your engine ? If not I suggest putting that on quick,,,, about $36 dollars I think...

Second, lets don't use the phrase " tearing into"...lets say " carefully disassembling " .

Those guys were just not interested in messing with it because they make more money selling their own stuff... MOST BEARINGS HAVE BEEN METRIC FOR 20 years....

Get to the library before you take it apart... so you know what to look for with respect to brushes if it has them... and take lots of pictures as you open it up.. another person taking the pics would be ideal... When you get it open post the pics... put a couple of drops on the shaft and leave over night in a position where it will drain onto the bushing.. do it for each end since you don't know which is binding...

See if you can find a copy of " How To Fix Damn Near Anything " it is a great book because it also deals with diagnostic philosophy and methods... and has a great section on electric motors as well... Greg

I edited this to show the correct number of blades for the new engine fans..... 9 !

I would just buy an aftermarket fan from Pepboys. I look at it this way: you get a new fan for far less than a MB replacement, it comes with a new relay and wiring harness, it is newer, so it likely operates better (i.e., more quiet and better design to the fan blades), and you can buy a larger one that pushes more air (which will give you better a/c operation and engine cooling). I don't think you can loose. This is what I plan on doing on my car, especially since I can buy a huge fan to blow lots of air to give better performance of my r-134a-converted a/c.

Good Luck,

Greg
'84 300D

GEE, GregS, Where is your "Spirit of Adventure" ?
Sure that would work great, but you would not know anymore about electric motors at the end of the experience....

Just replace it with a good used one. Don't dink around with aftermarket electric fans, it's almost guaranteed they won't fit right, and guaranteed to look cobbled on. The factory fan looks, well, factory. I just swapped a used one on to my car, it works great. Found a mint one at Pick-n-Pull for ~$20.


Two other things to remember for W123 chassis cars:

1- The fan does NOT come on when the engine is hot. There is no connection whatsoever to engine temperature.

2- The fan ONLY comes on when the A/C refrigerant pressure (high side) reaches the set point of the pressure switch. So when the A/C is on, the fan may or may not run, this is NORMAL. It is more likely to be on when hot outside and with a full charge. It is more likely to be off if you either have a low charge or in cooler ambient temps.


Silver Star motors in central CA sells the fans for ~$50 with a 6-mo warranty, and there's a guy on the east coast on the MBZ diesel list that will sell them even cheaper (no wty tho.) I thnk new ones are ~$100+.


Regards,

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Dave
Boise, ID
Check out my website photos, documents, and movies!

My closest "pick and pull" is a 200 mile round trip.... an hour messing with the broken one might fix it for a couple of dollars on the bushing... why not try that first... then you still have a factory unit which will look, well, factory....

Take it apart:p If ya can't fix it at least you will learn something about how they work. Don't forget about Allums down on 24th street south. Best U-pull place in the area for benz parts.

The OEM fans are pretty big, but also designed to efficiently flow air when not running. I second the advice not to use aftermarket fans. New ones are pretty darned expensive - hopefully you can find a nice used one from a car in the snow belt that has had little use.

When I see someone parting out a car here or on EBay I start asking questions about the items I need. Have gotten good deals that way.

Don't let the car run hot, but 90c isn't hot in my book.

Ken300D

Ryan,

Leathermang (Greg) gave some pretty good advice. There is relatively little to an electric motor and yours sounds like a bearing problem. A good synthetic penetrating oil will soak into the porous bushings and reestablish their origninal bearing qualities for a reasonable period of time. Once these things loose their initial impregnation of lubricant though, they tend to need a more regular lubrication servicing.

If you were able to get it to run by helping it a little by hand, the chances are the static friction of the bearings exceeds the starting torque available. This is a pretty typical failure mode, as the initial break away torque demand is greater than the running torque and the motor typically struggles to make torque at start up if the starting position is unfavorable due to the details of the motor pole geometry. The solution is to reduce the break away torque requirement, and that means new bearings and journal surfaces, and/or a lubricant. If the journal surfaces are scored the lube will not be effective.

As things age the windings in the motor suffer a little insulation degradation (heat and aging) which may reduce their performance somewhat, and the same is true for the bearings. If you need a rewind, get a junker from some other car as I would not expect a decent rewind job to be less than a used assembly from a junked car. I don't know if these things have brushes or not, but brushes are cheap if they are worn out (couple dollars). You may have to file or sand them to the right shape, but that is not a lot of work.

If you find the motor ingested some debris and there is some crud interfering with the movement of the rotor, that is an easy fix unless it has damaged the bearings or windings. Just check it out and if you completely ruin the thing, you did not loose much. Between my two sons and me, very little non-functioning things leave the house for recycling or the dump in anything like the condition they arrived in - my son has even taken apart hard drives and CD players and kept stuff he thought "he might use" later. Got lots of unidentified stuff now that only he knows what it might be.

The point is, a cleaning, possibly new brushes and lubrication might solve the problem. If it needs more I would get another motor/fan assembly. Good Luck, Jim

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Own:
1986 Euro 190E 2.3-16 (291,000 miles),
1998 E300D TurboDiesel, 231,000 miles -purchased with 45,000,
1988 300E 5-speed 252,000 miles,
1983 240D 4-speed, purchased w/136,000, now with 222,000 miles.
2009 ML320CDI Bluetec, 89,000 miles

Owned:
1971 220D (250,000 miles plus, sold to father-in-law),
1975 240D (245,000 miles - died of body rot),
1991 350SD (176,560 miles, weakest Benz I have owned),
1999 C230 Sport (45,400 miles),
1982 240D (321,000 miles, put to sleep)

i fixed the fan for a whopping 4 dollars and 28 cents!!! i took the fan apart, found the front bearing was the bad one, drilled out the riveted on plate, had "Terry Bearing" press in a new bearing and glue it in, re-assembled the fan and it works. Grand total was only 4.28!!! its much quiter, it doesnt' seem like it's spinning as fast but its probably just because it's actually quite for once. Rebootit: also give rick's european on 66th street and 114ave a shot, they have IMO better condition parts at similar prices. i've gotten good deals at both, rick's is a little more open to haggling. I normally pay a little under half what a new part would be. Thanks for all your help, if anyone is interested i can do a write up on it!! It really pays to do stuff yourself!
Ryan

__________________
83 300SD.......sold
96 integra SE....sold
99 a4 quattro....sold
2001 IS300.......sold
2002 330i.........current.
2004 highlander limited....current.

that fan must be working MUCH better, the temp doesn't rise as much at idle, and the a/c blows colder at idle as well. There is still some side to side play, but it is coming from the fan casing itself, not the motor? i may have to figure out some sort of spacer or something with that. that was the best 4.28 i've ever spent!
Ryan

__________________
83 300SD.......sold
96 integra SE....sold
99 a4 quattro....sold
2001 IS300.......sold
2002 330i.........current.
2004 highlander limited....current.

I have a 123 car and the fan came on the other day. It stayed on regardless of the A/C until the engine cooled down. Am I imagining this?

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1982 300D Turbo "Helga"
380,000 miles

You remember "HAL" from 2001 ? I am convinced that some of these cars have minds of their own... so that does not surprise me.... the buttons on my dash just do whatever they want to do ... with no regard to my wishes... Greg