Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help




Go Back   PeachParts Mercedes ShopForum > Technical Information and Support > Tech Help

Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 04-28-2003, 01:15 PM
haasman's Avatar
Registered User
 
Join Date: Jun 2001
Location: San Francisco, CA
Posts: 3,097
190E Aux fan-stays on all the time

I searched the threads but most of the postings were regarding the Aux fan not coming on. My stays on all the time. I did wash the engine over the weekend so is this result from soaking the sensor on the engine?

I stopped the fan from coming on by pulling the single connector from the sensor farthest forward on the engine.

Is this sensor bad or is something else triggering the Aux fan? It runs fast and is very loud (high speed?).

Thank you in advance,

Haasman
__________________
'03 E320 Wagon-Sold
'95 E320 Wagon-Went to Ex
'93 190E 2.6-Wrecked
'91 300E-Went to Ex
'65 911 Coupe (#302580)
Reply With Quote
  #2  
Old 04-28-2003, 01:56 PM
haasman's Avatar
Registered User
 
Join Date: Jun 2001
Location: San Francisco, CA
Posts: 3,097
Here is the sensor picture with the wire detached ....
Attached Thumbnails
190E Aux fan-stays on all the time-dscf0003-small-small-.jpg  
__________________
'03 E320 Wagon-Sold
'95 E320 Wagon-Went to Ex
'93 190E 2.6-Wrecked
'91 300E-Went to Ex
'65 911 Coupe (#302580)
Reply With Quote
  #3  
Old 04-28-2003, 02:55 PM
Registered User
 
Join Date: Sep 2002
Location: Kingsport, TN
Posts: 375
Hi Haasman,

could the sensor/connector be wet and it shorts around the connection? May be drying and dielectric grease?

Good luck

Reinhard Kreutzer
Reply With Quote
  #4  
Old 04-28-2003, 02:58 PM
Registered User
 
Join Date: Sep 2002
Location: Kingsport, TN
Posts: 375
Come to think of it, I think you can test the sensor with a digital meter for continuity, i.e if resistance is close to 0, sensor is bad.

Reinhard Kreutzer
Reply With Quote
  #5  
Old 04-28-2003, 03:06 PM
haasman's Avatar
Registered User
 
Join Date: Jun 2001
Location: San Francisco, CA
Posts: 3,097
Reinhard

Thanks for the replies. I did try and dry it and I am letting it sit after running.

Regarding testing it: There are three connectors, the one I pulled off to stop the fan. Is this the one that should be tested?

Haasman
__________________
'03 E320 Wagon-Sold
'95 E320 Wagon-Went to Ex
'93 190E 2.6-Wrecked
'91 300E-Went to Ex
'65 911 Coupe (#302580)

Last edited by haasman; 04-28-2003 at 03:50 PM.
Reply With Quote
  #6  
Old 04-28-2003, 07:10 PM
Registered User
 
Join Date: Sep 2002
Location: Kingsport, TN
Posts: 375
Hi Haasman,

let me first say I don't have your car and I am not the world's greatest electrician either, but here is my attempt:
from your picture, it looks like the wire you have taken off brings the electricity to the switch, so I would test that for current. The other 2 should not have current. Then I assume the current will flow out through one of the other pins, depending on the temp. So I would test for continuity between the pin you have exposed now and the other 2. If you have zero resistance, that would mean that current would always flow through that wire (and that wire hopefully goes to the fan motor).

Your picture also seems to show some insulation missing to the right.

I hope I am not leading you into the wrong direction. Any other "electricians" out there feel free to chime in.

Reinhard Kreutzer
Reply With Quote
  #7  
Old 04-28-2003, 07:57 PM
Senior Member
 
Join Date: Sep 2002
Location: So. Calif.
Posts: 323
If you just washed the engine . . . you got WATER in the sensor.

It will take a week or so for it to dry out . . . Once it dries . . . Take some silicone and SEAL the seam where the BRASS crimps around the PLASTIC . . .
Reply With Quote
  #8  
Old 04-28-2003, 08:31 PM
haasman's Avatar
Registered User
 
Join Date: Jun 2001
Location: San Francisco, CA
Posts: 3,097
Thank you Reinhard. I believe that the disconnected sensor wire connects to a relay which directs the power to the fan. The fan consumes a lot of power and the relay could not handle all of that juice.

What I am trying to understand is there something else in the circuit which would tell it to go on, such as a faulty high-pressure sensor on the AC or something.

Regarding the wire that looks like it has insulation coming off, it is actually the brown covering, but in this bad picture it looks like bare copper. See the second picture.

mpnye- I will wait a week and see if it dries out. That sounds like a good possibility. If so, I will dress it with silicone.

Thanks for the replies all. I will update the post when it starts behaving itself again or another solution is found.

Haasman
Attached Thumbnails
190E Aux fan-stays on all the time-dscf0005-small-.jpg  
__________________
'03 E320 Wagon-Sold
'95 E320 Wagon-Went to Ex
'93 190E 2.6-Wrecked
'91 300E-Went to Ex
'65 911 Coupe (#302580)
Reply With Quote
  #9  
Old 04-28-2003, 09:31 PM
Registered User
 
Join Date: Sep 2002
Location: Kingsport, TN
Posts: 375
Hi again,

on my 126 there is a pressure switch at the ac unit and it looks like the attached picture on the driverside front of the car.

But mpnye has it probably right and the water might dry out. While it's wet, it should show 0 resistance though...
Attached Thumbnails
190E Aux fan-stays on all the time-ac-pressure-switch.jpg  
Reply With Quote
  #10  
Old 04-28-2003, 10:22 PM
Gilly's Avatar
Registered User
 
Join Date: Mar 2001
Location: Evansville WI
Posts: 9,616
The engine temp is what makes the fan come on at high speed.

The AC switch makes the fan come on at low speed only.

Gilly
Reply With Quote
  #11  
Old 04-29-2003, 03:09 AM
haasman's Avatar
Registered User
 
Join Date: Jun 2001
Location: San Francisco, CA
Posts: 3,097
RKreutzer

The 0 resistance is measure between the single-pole on the sensor and ground?

Haasman
__________________
'03 E320 Wagon-Sold
'95 E320 Wagon-Went to Ex
'93 190E 2.6-Wrecked
'91 300E-Went to Ex
'65 911 Coupe (#302580)
Reply With Quote
  #12  
Old 04-29-2003, 03:24 AM
irieite's Avatar
Registered User
 
Join Date: Nov 2002
Posts: 157
My '91 190e has a similar problem, although I didn't wash the engine. The Aux fan will come on high even when the engine is cold started and the A/C is off. The A/C has been converted to 134a (before I bought it) and I know that the 134a operates at a higher pressure than the old r12, but would this cause the fan to come on even with the A/C switched off and engine cold??
Reply With Quote
  #13  
Old 04-29-2003, 03:51 AM
Senior Member
 
Join Date: Sep 2002
Location: So. Calif.
Posts: 323
Quote:
Originally posted by Gilly
The engine temp is what makes the fan come on at high speed.

The AC switch makes the fan come on at low speed only.

Gilly
Here in the desert of So. Calif. I modify the wiring at the Aux. Fan Resistor so ALL the wires are connected TOGETHER so the Aux. Fan runs on HIGH for the A/C High Pressure Switch to reduce HIGH SIDE PRESSURE . . .
Reply With Quote
  #14  
Old 04-29-2003, 05:25 PM
Registered User
 
Join Date: Mar 2003
Location: New York
Posts: 101
Definitely the sensor is your problem

Hi Hassman,

If you get 0.0 Ohm from the single pole to ground then the sensor is shorted. When the sensor is cold you should get Mega to infinity Ohm.
This sensor properly gonna cost you around 50 bucks. And don't worry about other things because you said it, when you remove the connector to the single pole the Auxilary fan stops!
Reply With Quote
  #15  
Old 04-29-2003, 05:40 PM
haasman's Avatar
Registered User
 
Join Date: Jun 2001
Location: San Francisco, CA
Posts: 3,097
Thanks 16VAlex and everyone for your replies.

I always learn things on this site!

Haasman
__________________
'03 E320 Wagon-Sold
'95 E320 Wagon-Went to Ex
'93 190E 2.6-Wrecked
'91 300E-Went to Ex
'65 911 Coupe (#302580)
Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On




All times are GMT -4. The time now is 04:58 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2011 Pelican Parts - Posts may be archived for display on the Peach Parts or Pelican Parts Website -    DMCA Registered Agent Contact Page