I HAVE A 88 190E 2.3 THAT OVERHEATS WHEN CAR IS NOT MOVING THE ELETRIC FAN WILL COME ON BUT MY ENG DRIVEN CLUTCH FAN I HAVE YET TO SEE BEING DRIVEN. HOW DO I TEST THE CONTROLLING WIRING OR CLUTCH. DEALER SAID IT WORKS AS BUILT I THINK NOT
THANKS

The 2.3 has an electromagnectic fan not a clutch. It kicks in at 105C give or take depending on year. If its cool enough outside and your radiator is old it will just hover in heavy traffic near the 100C mark and never trigger the fan...annoying as hell.
I think your dealer is wrong the mini electric fan should not come on before the big electromagnectic fan. The mini fan kicks in at a 5 degree higher temp and complements the big fan or when the AC is on.

The fan switch for the electromagnectic is screwed into the top of the the engine behind the oil cap. If you are going to order a new one make sure you give your vin number so you get the right one.


Here are some threads that discuss this:

92 190E 2.6 Overheating Problems

Aux. Fan advice requested.

cooling system wiring




[Edited by yal on 04-12-2001 at 01:50 PM]

Is there a way to test the switch that controls the main fan?

Hello all,
I was wondering if someone would answer the question from Grant. My engine fan is never running, just spinning from the air that goes across it. Today I removed the plug coming from the clutch and hooked a lead up to the positive terminal of the battery. Nothing. I would imagine that there would be some "click" or something from the clutch engaging. Can anyone tell me if this might be true? This is killing me. I don't want to replace the clutch if it isn't necessary. Thanks for any responses.

Kyle

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1988 190E 2.3 (178,000)
FastLane, PartsShop and this forum rule!!!

Kyle, read my explanation above carefully. The fan on a 2.3 engine is not clutch driven. It is an electromagnectic fan. It is triggered by a fan switch that sits just behind the oilcap on top of the engine. It comes on at about 105 on the Temp guage.

Yal,
thanks for the reply. Do you mean the oil cap on top of the valve cover? Mine has nothing there. I am going crazy with this. I have an hour commute and drove it home tonght with the temp going to about 87 or so. The outside temp is about 80 and there is very little stop and go en route. When I was about 10 min. from home I decided to crank the A/C. The temp went up to 115 or so and the air coming out of the vents was sometimes cold and sometimes not so cold. I hope this scenario will help diagnose the problem. Like I said, it's driving me crazy. It will run o.k. but I know it's not right so I have to fix it. Please help with any suggestions.

Kyle

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1988 190E 2.3 (178,000)
FastLane, PartsShop and this forum rule!!!

Semantics, I would call it an electromagnetic fan clutch but whatever you call it the darn thing should come on earlier. As it turns out when using the A/C the car actually stays cooler as the electric fan will come on with hi side pressure way before the engine gets to 100deg C.

The single pole switch for the fan is usually on the water pump. It is as big around as a quarter, cylindrical and an inch tall with a red top and a single male terminal. I take every one I see and wire the thing straight to ground so that the clutch is always coupled.

I do that since there are no 90 deg C switches; which would make it usefull.

__________________
Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician

Steve

I'm chasing a short in my car.

Fuse #10 blows, so no tach.

Disconnected fan clutch sensor wires (2 prong type) on the valve cover and fuse still blows.

Disconnected fan clutch wire below air filter housing and fuse does not blow.

Got my tach back!!!

So the short is either in the wires or there is a fault with the electromag clutch (unlikely) itself.

You mentioned the switch for the fan on the water pump. Is this applicable for my car?

Azhari
Babybenz 1991 190e 1.8

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"I was wondering if someone would answer the question from Grant. My engine fan is never running, just spinning from the air that goes across it. Today I removed the plug coming from the clutch and hooked a lead up to the positive terminal of the battery. Nothing. I would imagine that there would be some "click" or something from the clutch engaging."

Kodiac, it's not clear to me how you are testing, but if you only hooked up one wire, the clutch won't work. One side goes to ground, and the other side to 12V. A quicker check would be to locate the fan temperature switch, which probably has only one connection. The switch connects this connection to ground, and you can test it by connecting this to ground while the engine is running.

Yal, the electromagnet fixed to the front of the water pump pulls on an iron disc attached by spring on the fan, which then engages the pulley face. This IS a clutch. The engagement clutch on the A/C compressor works the same way.

Steve

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Anyone know the pipe tap thread on the OEM?
I might be able to track some lower cut-in ones down from another Mnfg....

I took the lead on my clutch and hooked it up to 12V while the other remained bolted to ground on the engine (checked to make sure contact was good). Started the car, and nothing...the fan still free-wheels. I am thinking that either wires may have become open circuit due to the short (the wires looked burnt).

If I could renew the wires directly from the clutch (is it a connector on the clutch coz it's hard to get at), I could be sure if the clutch is gone...

Any thoughts anyone?

Azhari
Babybenz 1991 190e 1.8

Read this, I posted pictures of the fan switch and described how to test it

good luck!

overheating troubleshooting 84 190E

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190E's:
2.5-16v 1990 90,000m Astral Silver
2.0E 8v 1986 107,000m Black 2nd owner
http://www.maylane.demon.co.uk/190esmall.jpghttp://www.maylane.demon.co.uk/190esmall2.jpg

Azhari, if the 1.8 is the same as the 2.3, the fan and pulley are easy to remove to gain needed access. Beware though of the old idler tensioner mechanism - mine broke (deteriorated rubber) while retensioning the belt.

Water pump, engine mounts, tensioner shock 190E?

for my thread.

Steve

Hiya Steve.

Since you've ever taken out the electromag clutch, I wonder if the wiring loom from the clutch is de-tachable so I can test it.

There was a short once which resulted in the wires connected to the sensor burning. I noticed the smokin' wires before it anything BAD could happen (i hope) and took them out.

Then I lost the tach, powered rear view mirror, etc due to fuse #10 being blown.

Next, I disconnected the supply wire to the clutch (round connector) beneath the air filter housing and tried replacing fuse #10 again.

It was OK so I have the tach and stuff back again, but no clutch fan.

I noticed that the insulation of the 2 small wires (ground and +12V) going back to the clutch seemed to have burnt out in a couple of spots and that the wires are pretty stiff (due to the heat, i guess).

Put +12V directly to the supply wire of the clutch (with the engine running and the ground wire connected) and still no clutch fan.

Which brings me back to my first question, whether these wires can come off the clutch (via a connector) so I can renew the wires. If not, we could be looking at a fan clutch replacement, which I think may not be necessary unless the clutch itself has been damaged beyond repair due to the short. I want to be sure before I take the leap.

Thanks for your tips Steve. I hope you can shed some light on the clutch wiring issue.

Yipeekiyay!!!!!:p

This is fun...

Azhari
1991 190e 1.8

I have this same problem too. The engine fan barely spins and I can stop it with my hand. I want to know if I need a new clutch. Im thinking about getting rid of the whole clutch setup and buy a flex fan or something and have that constantly run.