Fan Control Relay

[rees_A]

I have seen a number of threads suggesting that when the fans on the front of your car fails, its the fan control relay that needs replacing... Has anyone actually had this problem and found that replacing the control realy has fixed it. I don't want to waste £100 if its not that so any info from those of you who have replaced it would be great...

 

[silverarrow]

yep change it take the screws out of the old one and see all the rust and damp

 

[griffin5]

Yes, for around a tenner it got my fan back running and it's a DIY job to change.

 

[jagr]

My '94 E280 has had an aftermarket Diavia aircon system fitted,
Will this has the fan control relay under the passenger front wing?
My front fans do not come on at all?

Thanks

 

[rees_A]

Getting confused now.... Just spoke to mercedes who said the fan control relay is a small green relay located behind one of the headlights? The cost of the relay is £16.20. Can someone please confirm that mercedes are right or is it under the front wing as I've previuosly been told..... Also, I was told they were £95. Are Mercedes quoting for the wrong part or have they reduced it/is it different on my W202 96 C36 than others???

Any help before lunchtime would be great as I want to go buy one to get it fixed...

 

[silverarrow]

defn under the front wing have a look you will see it it has one large connection block with approx 15 wires going in to it it is well known to fail and no obc fault code stored
mbz will not give a fan control relay without a chassis number because they want to monitor how many fail ie possible warranty claims for engine damage ie over heating ie cyl head
i had the same problem getting the part but it has been up graded ie mbz have modified it ???? they know its duff
a relay with all that water and dirt ??? what a daft place to place in the first place

 

[silverarrow]

you may find mbz have on the computer system that the box under thr l/h/s wing front is called the electronic control module
but to all in every day it is a relay

 

[rees_A]

Have ordered a fan control relay now...Not sure what it is, will go to mech tomorrow to have it fitted....Hopefully its the right thing....

 

[silverarrow]

progress report pls

 

[jasohal]

don't want to confuse the issue but on my e320 w124 model, a blue relay in the back part of the 2 part fusebox has a 15 amp fuse in it.

After reading this article I thought I'd test out my aircon and front fans - they didn't work !!!

Looked through the fuses and replaced the broken 15 amp fuse on the blue relay and now they are working when the A/C is on and the engine reaches a certain temp.

 

[silverarrow]

fuse on a c class w202 has several components interlinked thus when a fuse blows it is easty to check which fuse has blown
normally fuses blow for a reason they are not the cause of the fault but an indication of a fault
when the fan control relay plays up no fuses blow just the car runs hotter ie it has a fail safe setting same as when a maf goes
obc is useless with mafs and other components that are in the process of failing modern cars need time on diagnositcs so many garages start to change this then that then this and then that ie £££££££ and loads of labour even main agents do it