I have a 2008 Mini s, and recently was troubling shooting my AC. I discovered my engine cooling fan was also not working. Found a missing fuse, FL9, a 50 amp fuse for the engine cooling fan. Placed the fuse in and everything works. However before the fuse, I was running at 190-200F coolant temp. Now im running 215-225F (AC off) and 190-200F (AC on). I am puzzled by the this change. Does anyone have any ideas as to why?

 

Well, I'll start by saying your AC off temperatures sound about right: these cars run pretty hot by design. The thermostat is electronically controlled, and when you turn on the AC or engage sport mode the computer runs the engine cooler.

That said I'm a bit puzzled here. Was the fan running at all with the fuse not in place? I'm kind of surprised it wasn't overheating when not moving in that case. And the fuse was just...not there? How long have you had the car?

Anyway, my WAG is that maybe the computer detected the fan circuit was open and controlled the thermostat cooler to compensate, but that's the best I've got without more details. If I have time I'll take a look at the wiring diagram, see if I can come up with anything more clever on that fuse.

 

Thank you Gubi, I am unsure if the fan spun while driving, but I do not think so. It definitely did not move while sitting. Car would definitely get HOT when sitting, but I live in a cool climate and this is my first summer owning it so it never got that high. The Fuse FL9 was completely missing. I did have a water pump failure so youre guess that it was compensating sounds possible. Thanks for the insight

 

Okay, so if I'm looking at the right wiring diagram (MCS N14 engine) it's a two speed electric fan. F08 (40A) feeds low speed and F09 (F09) feeds high speed. So without F09 you still should've had a working cooling fan, just only at low speed.

They're both triggered by the DME unit and I'd guess that could detect an issue of the fan not getting power? So my guess is that the DME just switched to lower temperature operation when it detected the high speed fan setting was not working.