Excessive heat generation - but not in the way you may expect.

[Gianni682]

I just purchased a Mini One as my daughter's first vehicle. When the engine is in an idle state after being run, it will experience overheating due to the low-speed fan not activating.
Although the issue has been well documented, the available solutions only address a 3-wire setup, but I am dealing with a 2-wire setup. Is there a solution available for this wire? The wires are in excellent shape, with one end connected to the motor and the other end concealed behind a wiring loom. Thank you.

[Gianni682]

[WhisperingWillow]

I am uncertain about the specific method you are applying, but the optimal course of action is to replace the resistor. This option is cost-effective and will restore the automobile to its original functionality.

[Gianni682]

I concur, however, it is worth noting that this particular automobile is equipped with just two wires that provide power to the fan, rather than the expected three. This observation implies that the resistor is not situated in close proximity to the fan.
Additionally, these two lines are concealed inside the wiring harness under the fuse box. I am encountering difficulty in locating any online documentation pertaining to this specific wiring configuration. The issue is that the 2004 R50 model should have a wiring loom that is different from the one it now has.

[johnmayerrr]

Is the coolant exhibiting a vigorous bubbling action and being expelled from the reservoir?
I recently had an issue with my R50 vehicle. The seal on the cap of the thermostat housing had deteriorated, resulting in a lack of pressure. Consequently, the coolant did not reach the required temperature for the fan to activate.
I was able to resolve the issue by using a new cap. It is worth trying considering their affordable price.

[WhisperingWillow]

The occurrence of cooling fan failure at low speeds is prevalent across all age groups, regardless of whether the fans have two plugs or one plug. I had presumed that both had the resistor, as shown by the presence of a protrusion in the fan housing. If just the low speed function has stopped working, the most likely cause is a malfunctioning resistor. However, it is also possible that the relay is responsible, although the resistor is often the component that becomes damaged.

However, this eBay advertisement seems to display a relay located inside the fan housing, which might perhaps be the source of your failure.

BMW MINI COOPER R50 R52 2001-2008 PETROL RADIATOR COOLING FAN. 2 PLUG | eBay

[WhisperingWillow]

johnmayerrr might also be a valid explanation - in the absence of pressure in the cooling system, the temperature will not rise to the required 104C to trigger the activation of the low speed fan. However, it will reach its boiling point at 100 degrees Celsius.

[Gianni682]

I have been informed that the problem is most likely related to the thermostat, and replacing it should resolve the issue. While I am doing that, I will also inspect the seal. Thank you.
However, it seems that the fan is only equipped with a single speed. I speculated that the fan may be equipped with dual speed functionality, and that the resistor might be concealed in an undisclosed location.

[johnmayerrr]

I purchased a thermostatic housing that included a new thermostat and cap, and I performed the same thing.
After seeing the significant inferiority of the previous cap, I decided to test the new cap as a first step. Surprisingly, the new cap successfully resolved the issue without requiring any more modifications.