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-Benz Forum > Mercedes-Benz Tech Information and Support > Tech Help

Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 05-16-2007, 10:31 PM
Registered User
 
Join Date: May 2007
Posts: 1
electric fans going wild

on my 91 103 eng 124 body anytime the outside temp is above 60 deg when I start the car both fans come on,sometimes they come on by just turning the key to on. I have no idea where to start.I inspected my aux fan relay ,it looks ok so does the ceramic resistor. Pls help Thanks

Reply With Quote
  #2  
Old 05-16-2007, 11:04 PM
Registered User
 
Join Date: Jan 2005
Location: St. Louis Missouri
Posts: 473
Don't know if your car is the same as mine (95 E320)--if so, one of two things make the fans come on. 107C coolant temperature or refrigerant pressure of about 22 bar. Coolant temp is provided by a thermistor, ac pressure info is provided by a pressure switch. If either the pressure switch or thermistor are faulty, it could result in fans coming on when they should'nt.... Also, it could be a shorted relay but you said the relay was OK. (My vehiclew has two relays, one for temperature activation of fans, and one for ac pressure activation of fans)

If the temperature is less than 60, do the fans come on shortly after startup, or do they stay off?

Last edited by J. M. van Swaay; 05-16-2007 at 11:10 PM.
Reply With Quote
  #3  
Old 05-17-2007, 12:02 AM
Registered User
 
Join Date: Aug 1999
Location: Florida / N.H.
Posts: 8,804
Check the connector at the blue 2 wire sensor..if there is an poor connection there [ common] , the N22 module defaults to running fan
[ engine overheat protection circuit].
Second test is next time it does it, disconnect the pigtail wires at the pressure sw ..if fan stops , pressure sw is bad.

It will make it much easier to diagnose if you tell us if it is a High speed fan or low speed fan.
The blue sensor is in the high circuit, the pressure sensor is in the low speed circuit.

Last edited by Arthur Dalton; 05-17-2007 at 12:12 AM.
Reply With Quote
  #4  
Old 05-17-2007, 03:15 AM
Registered User
 
Join Date: Jul 2004
Posts: 187
Check temperature sensor on the 104 engine it's on the waterpump housing on the 103 engine I don't now.

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 02:23 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2021, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2018 Pelican Parts, LLC - Posts may be archived for display on the Peach Parts or Pelican Parts Website -    DMCA Registered Agent Contact Page