Aux Fan wiring question

[tjpike]

Hi everyone,

does anyone know what each pin in the aux fan plug does? Is there a wiring diagram for this? And also how can I take the pins out? are they replaceable?



Not my picture, but this is the plug I require info about.

Thanks in advance

[tjpike]

Anyone?

[Mayorchuck]

https://www.bimmerforums.com/forum/s...1#post27641431

You will need a browser extension like Photobucket Fix to see the schematic.

[tjpike]

Thanks for the reply mayorchuck. I understand that the black wire is 12v and brown is negative. But do you know what the blue and red ones are? One has got to be from the DME.

EDIT:

Looks like pre facelift cars have 4 connectors and post have 3 in the same plug. So i guess this means that the 3rd would be from the DME.

[kouks]

Brown is ground, the blue and the part red are for high speed and low speed fan. Not sure which is which.

[kouks]

OK,
1=ground
2=low speed relay
3=high speed relay
4=power (fuse 78)

Hope that helps

[tjpike]

Thanks for the reply kouks, that is exactly what I wanted to know, but my question is that the facelift cars have 3 pins in the connector like the E39s, like below:



In this case, there are only 3 pins, so the 3rd pin would be from the DME instead of the relays right?

[kouks]

All the wiring diagrams I'm looking at, even e39, show 4 pins.

This may help on wiring diagram colors.

Color - function

Black - Fuse 75 power
Brown - Ground
Black/green - high speed relay
Black/brown - low speed relay.

Actually, thanks for bringing up the subject, my aux fan is dead and my e39 one doesn't work when the AC is on, but works when the coolant gets hot, so I need the info too.

[Mayorchuck]

Electricfan.jpg~original.jpg

Electric Fan

Vehicles with M62TU, S62 and M73 engines feature a viscous fan as well as an electric fan. The electric fan cuts in when the cooling capacity of the viscous fan is no longer sufficient.
The electric fan is activated by means of a power output stage directly on the fan motor. The motor control unit activates this power output stage by means of a square-wave signal with duty factors (variable pulse width) between 10 % and 90 % thus controlling the various speeds of the electric fan. Pulse duty factors less than 5 % and greater than 95 % do not trigger activation but rather they are used for fault detection purposes. The power output stage features its own positive and ground supply.
The fan speed is influenced by the coolant temperature at the radiator outlet and the pressure in the air conditioning system. The fan speed is reduced as the vehicle speed increases.
If a fault occurs during operation a corresponding fault code will be stored in the fault code memory of the DME control unit.
For the purpose of checking operation and troubleshooting, the diagnostic program offers the option of activating the electric fan directly via the DIS tester/MoDiC.