Tested the auxilary radiator fan with external power and the motor works fine, but fan does not come on when hooked to car. Checked the parts catalog and it only shows an auxilary fan switch for a 1979 450SL not SLC. Does the SLC have a fan switch and if so is it the same as the SL? Is the auxilary fan switch the likely culprit for the fan not coming on? I have not tested the power source all the way back.

Thanks. SMW

The switch is a common issue.
Disconnect the switch, run a jumper between body feed wire and fan, test system.


Vehicle: 1979 Mercedes Benz 450SLC
Part: A/C Temp. Switch
------------------------------------------------------------------
A/C Temp. Switch
California
2 spade terminals on short pigtail. Chassis: -019056
--------------------------------------------------------------------
A/C Temp. Switch
Federal
2 spade terminals on short pigtail. Chassis: -019097
---------------------------------------------------------------
A/C Temp. Switch
@ receiver drier
California
Located on receiver drier for auxiliary cooling fan. Identified by 2 spade terminals on short pigtail with red base. Chassis: 019057-
----------------------------------------------------
A/C Temp. Switch
@ receiver drier
Federal
Located on receiver drier for auxiliary cooling fan. Identified by 2 spade terminals on short pigtail with red base. Chassis: 019098-
------------------------------------------------------------
A/C Temp. Switch
@ receiver drier
Located on receiver drier for auxiliary cooling fan. Identified by 2 spade terminals on short pigtail with red base.

http://catalog.eautopartscatalog.com/mercedesshop/sophio/wizard.jsp?partner=mercedesshop&clientid=catalog.mercedesshop&baseurl=http://catalog.peachparts.com/&cookieid=1QC0Y25IE1QU179RTA&year=1979&make=MB&model=450-SLC-002&category=R&part=A%2FC+Temp.+Switch&appChassis=_any


Have a great day.

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Just to be sure, are we talking about the same thing. I am looking at one part called an aux. fan switch and the name of the parts you are referencing are a/c temperature switches. SMW

Typical issue is the switch = A/C Temp. Switch.
Located on receiver drier for auxiliary cooling fan.

Try grounding the 212 degree switch on the T stat housing

Yes the SL's and SLC's have identical systems. You are inquiring about the 212 F. switch on the thermostat housing. I have a 80 SLC and experiencing the same issue. I will take MBTECH's advice and ground out the switch to the housing to see if switch is good. I believe when the vehicle temp. reaches 212F the switch closes and the fan activates. Grounding the switch will simulate that effect.

Yes, this switch is also a possible issue.

PART NUMBER SEARCH RESULTS WITH PRICES
Vehicle 1979 Mercedes Benz 450SL
Part: Auxiliary Fan Switch
Note: Temp. Switch for Aux Fan
212 Deg.
G5030-12319 Auxiliary Fan Switch Behr IN STOCK $31.83

http://catalog.eautopartscatalog.com/mercedesshop/sophio/wizard.jsp?partner=mercedesshop&clientid=catalog.mercedesshop&baseurl=http://catalog.peachparts.com/&cookieid=1QC0Y25IE1QV132ESC&year=1979&make=MB&model=450-SL-002&category=G&part=Auxiliary+Fan+Switch

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