BlackBear

I'm looking for the cooling fan relay.


I found one realay each in the glove box fuse box and the rear trunk fuse box. That is it. None of them are for the cooling fan.

So, where are rest of them?

530inOK

There's no relay. The DME contol drives the fan directly.

http://www.bmw-planet.com/diagrams/r...0e61/index.htm

Electric Fan
Under certain operating conditions, the engine control activates the electric fan at various speeds.

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.

Here's a pic of a bad fan motor driver,

BlackBear

Thank you for posting this information. Is it fair to assume that my fan is fried then? Or could it be a temperature sensor on the motor after all?

pcy

When you disconnect the connector [to the fan] and connect 12V directly, does the fan run?

BlackBear

No.

pcy

Then, I am certain the fan is dead. You will need to get a new fan. Call around - prices differ from dealer to dealer and on-line parts places as well.

530inOK

Not necessarily. You have to supply a signal on the small black wire (see photo in my first post). Is F9, 60A, in your front fuse holder good?
pcy may be correct about your fan. Checking further with a voltmeter, reading error codes, or substitution is your next DIY step(s).