thanks for the wiring diagram again.

This is my understanding from the diagrams.
pin 4- +ve connection to moter
pin 1- -ve connection to motor
pin 6- connection to 7.5amp fuse in fuse box F1/1
pin 3- X1/10 terminal box
pin 5- not sure ? Possibly sends signals to control module
pin 2- not sure? Also possibly sends signal to control module

and terminal 15 is terminology for 'always live with voltage'


I've just had another look at the connection and rechecked the voltaage

Ignition off
pin 1 - pin 6 12 volts
pin 1 - pin 3 12 volts
pin 6 - pin 5 12 volts

Ignition on
pin1 -pin 6 12 volts
pin1- pin 3 12 volts
pin6 -pin 5 0.5 volts

From this I can conclude that the unit is receiving power.

So the problem is either
1 - the suction fan control module is defective or
2 - the suction fan control module is not receiving a signal to tell it to switch on

I've been in contact with Mercedes London Canary Wharf. They are not helpful at all. They wouldn't even give the part number. The just want me to bring the car in to be looked at.
They can sell me the part for 134.00GBP (incl VAT).

I'm hesitant to buy the unit in case the problem is the unit not receiving a signal.

My next step is to drive the car until the temp > 100 degrees C. I can then recheck the voltages going to the module. I'm assuming a change in voltage to pin6- pin5.

If there is no change in voltage then, I will assume a signal failure and will hold off buying a new suction fan module.

The wiring diagrams are brillant and thanks very much sleepwalker for providing these. If you know where I can get a complete set for my car, I would be very appreciative.

I'll keep the site posted on how this works out.

 

I've just had another look at the N65/2 module and compared it to the N65/2 diagram.

They're in a different order.


This means, my pin numbers are wrong in the previous post.




[IMG]local://upfiles/12913/1F59B1B6C39B4A14A434904B555B944E.jpg[/IMG]

 

Looking at the plug, the order of the pins from left to right and using the circuit diagram are:

1 pin4 (fat red) - output +ve power to suction fan motor
2 pin3 (fat black) - input +ve
3 pin6 (thin violet/black) - input control module signal
4 pin2 (fat brown) - input -ve
5 pin5 (thin yellow/blue) - input control module signal
6 pin1 (fat blue) - output -ve to suction fan motor

I have power at all times from pin3 and pin2 (X4/10 terminal)

I have also just confirmed (engine hot)
that I have voltage signal being sent to the module. Pin6 and pin5.

I am now certain that the suction fan control module is defunct.

So will order this through the mercedes dealer. There is a one week wait onfortunatley.



[IMG]local://upfiles/12913/C42523411B8D48488FFBE86F0A36313A.jpg[/IMG]

[IMG]local://upfiles/12913/967AA13337DF4271803968422A8362DF.jpg[/IMG]

[IMG]local://upfiles/12913/5804312E61B14CED97EF3523B8829A70.jpg[/IMG]

 

I've just received my mercedes WIS manual and auto scanning tool.

I plugged it into the car and CODE 2073 flashed up.

I looked up 2073 and

guess what


- M4/3 electronic suction device

 

This is all very interesting, better than reality TV

 

Be sure that the aux. fan harness has been updated. This could be the cause of your problem. The harness update includes heavier gauge wiring and a 60A maxi fuse, instead of the smaller 60 amp mini fuse. This is a semi common problem for the 220 chassis. I have seen several catch fire when the smaller fuse melts and burns the wiring. You should go to the dealer parts counter and ask them to see the D.T.B.( Diagnotic technical bulletin) involving the aux. fan harness. This will list the parts needed to perform the repair, and the required procedure.

 

Thanks for the information. I'll look into updating the aux fan wiring harness when I order the suction fan control module on Monday. (I'd hate see my my hard work burn up on the side of the motorway)..

I've had to reinstall the Mercedes WIS sw 3 times now.. It looks like a great bit of SW, if I can ever get it to work.

It has wiring diagrams for every Mercedes since 1992. (apparently)

It also works off the Vehicle VIN number.

 

I've just contacted Mercedes Park Royal London.

Apparently, they don't make suction fan control modules anymore. (also call auxiliary control module)

If I want one, it will need to be a special order and may take 4 weeks to get.

The standard is to replace the electric fan motor with an integrated control module.

The cost £411. A lot more than the £135 I was initially quoted for the control module. DOH!



On a more positive note.

I've finally managed to get the Mercedes WIS SW working. It is truely fantastic. If anyone is considering doing work on their Mercedes, you should really consider getting this piece of kit..

 

Fixed!

I received the suction fan control module from Mercedes finally..

I've just installed it and taken the car for a long drive around London.

Engine temperature reached 90 degrees C and I pulled over to check the fan.

The fan was spinning away.

Fantastic.

Thanks very much Sleepwalker for your help on this.

If you ever make it toLondon, please send me an email. I owe you a few beers.



My AC light is on now, but I know that is another issue.

Cheers
A

 

Please, in the 300E 1988 where is the fan suction module?


Thanks

Mario Farias