electric fan wire routing - Mercedes-Benz Forum

LinkBack Thread Tools Display Modes
post #1 of 3 (permalink) Old 07-29-2008, 12:32 PM Thread Starter
BenzWorld Member
Rauchen's Avatar
Date registered: Jul 2008
Vehicle: 1971 Mercedes 280sel (w108)
Location: Nixa Missouri USA
Posts: 86
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
(Thread Starter)
electric fan wire routing

I have a 1971 280 sel. The electric cooling fan is wired to a small ceramic terminal block under the dash next to the hood release. The problem is the fan only comes on when one opens the driver car door. I know that is not the proper wiring for this, and would like to properly re-route the fan wiring. Also, I sure would like to know what that ceramic terminal block is for, cause there is nothing else wired to it. I'm trying to get this car back as original as possible, but over the years others have done some funny rigging. Any help sure would be greatly appreciated.http://www.benzworld.org/forums/imag...s/confused.gif
Rauchen is offline  
Sponsored Links
post #2 of 3 (permalink) Old 08-01-2008, 03:19 AM
BenzWorld Veteran
Date registered: Jun 2004
Posts: 723
Mentioned: 1 Post(s)
Quoted: 17 Post(s)
Do you mean the Auxillary fan on the front ? it should be wired hot to the fan and the earth runs through a temp. sensor on the thermostat housing(97 C). What happens quite often ,is the fan stops working and some clown cannot understand that there should be power at the fan all the time and they wire up the fan to some strange places. In your case it has been wired into the door switch . ( is there a grey and brown or red twin flex lead nearby ?) .

The fan should be wired from a relay through a fuse near your brake master cylinder. The fuse box is above the relay. Some cars have a safety switch there too. Power to the fuse should come from main fuse #2 . Depending on the cars build date it may also have a temp. sensor in the aircon gas line which turns the fan on when the tempo. gets too high(67c).In that case there will be two relays and fuse box. The fan and the aircon should have a fuse box,next to this is a relay for switching OFF the compressor clutch,a relay for aux. fan beside the safety switch . This safety switch turns the fan OFF when the hood is open,so when checking the fan ,use a bit of tape to hold the switch down...again this is a thing overlooked and is a cause of dodgy remedies to get the fan working.
mercmad6.3 is offline  
post #3 of 3 (permalink) Old 08-01-2008, 08:09 AM Thread Starter
BenzWorld Member
Rauchen's Avatar
Date registered: Jul 2008
Vehicle: 1971 Mercedes 280sel (w108)
Location: Nixa Missouri USA
Posts: 86
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
(Thread Starter)
mercmad6.3 thanks a million! Sounds like you know exactly what you're talking about. I'll check this out after work and hopefully get it working. Speaking of dodgy remedies, this same car had the factory fuel injection removed and a SU carburettor put in place of the throttle body on the existing intake manifold. Pretty squirrelly, but it does seem to work fine. Just not quite the horsepower I'd like. But that'll get fixed somehow. Again thanks a lot for you help.
Rauchen is offline  
Sponsored Links

  Mercedes-Benz Forum > General Mercedes-Benz Forums > Vintage Mercedes-Benz

Quick Reply

Register Now

In order to be able to post messages on the Mercedes-Benz Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:


Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode

Similar Threads
Topic Author Forum Replies Last Post
SL500 Wire Routing glennbaz Audio & Telematics Forum 1 12-17-2013 07:19 PM
w124 firewall wire routing peyton300td W124 E,CE,D,TD Class 4 12-12-2007 09:10 PM
Routing Wires/Wire color codes/location? Sergio W124 E,CE,D,TD Class 0 12-12-2005 10:26 AM
SL500 Wire Routing glennbaz R230 SL-Class 2 05-03-2005 09:06 PM
Has anyone gone to a electric fan??? I was thinking of going with a electric fan to free ... Prost2Benz W124 E,CE,D,TD Class 11 07-02-2004 08:02 PM

Posting Rules  
You may post new threads
You may 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 Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Title goes here

video goes here
description goes here. Read Full Story
For the best viewing experience please update your browser to Google Chrome