Cooling Fan Resistor
 

Hey Guys, I have an issue maybe someone can help out with.

2009 Mini Cooper Justa

The problem is the cooling fan/radiator. It is not maintaining the cars 82 C temperature like it should. Instead I have to turn on the AC in order for the radiator fan to turn on.

From research I guess there are 2 stages/speeds for the fan Low and High. I cannot seem to find a solution however. The forum only has minimal info for the R53 not the R56.

Any ideas on a fix? I heard somewhere you can solder in a resistor but I would love some information on anything at this point.

Please help me out! I am good at DIY and have minor experience in car mechanics but if I can figure out the issue then I can do more work on it to fix it.

Temps can and probably should go up to about 105C; these cars run hotter than many. 82C is about the lowest temp you want to see after the car is warmed up, and most of the time it is designed to run hotter.

So It is okay if the car hits a 100 C +? and this means nothing is wrong with the fan unit? The reason I ask is because water boils at 100C so I wasn't sure how that would work in the system and all.

The coolant is a mixture of antifreeze and water.

Pure water boils at 100C at one atmosphere of pressure. It boils at higher temperature at higher pressures. And our cooling system not only has a mixture of anti-freeze and water in it, but it is also under pressure.

220F is quite normal for our cars. I think that's right about 105C.

Thank you very much for this information. Its such a relief, I can drive normally again without having to keep the A/C on to keep it at 82C.

Fan and cooling stage 1 vs 2
 

Hi,


I've noticed lately with my AC on the fan spins very fast and then stops so I was wondering if i have this stage 1 not working issue with the AC off it doesn't spin up unless i'm in traffic, I have an older video where the fan was spinning up slower it is still loud but not as fast, I asked the dealer if this is going to cause damage to the engine they said as long as the fan turns on at some point it means it's still able to cool the car


although I don't drive my car that often at all so don't want to dish out $700+ just so I can have the piece of mind that the fan will work both stage 1 and 2. Could the fan work in stage 1 but spin fast because of the resistor has failed?


I have replaced the fan once under warranty in 2009 I have a 2005 cooper S.


Thanks


Anthony

That's because when you're in traffic you're not moving forward allowing cool air to flow through the radiator, when in traffic you get no cool air flowing over the radiator, that's what the fan is for and also after you shut off your engine. The fan comes on based on catalytic and coolant temperatures, you turn off your car and the coolant in hot weather will get even hotter now that no air is cooling down the cooling system.

The only time my fan kicks into ultra fast modes (speed 2) is when I have driven my Mini recently and I go to start it and turn on the AC, sitting in hot weather for 30 minutes your intake temps are about 140F when you first start it up again! The intake temps is do to the heat from the engine or else a cold engine would bring the intake temps down to ambient at cold start-up.

Hi






I took my car to the dealer again and they confirmed that the stage 1 fan was not working, my question is does that mean the stage 2 fan will only work when it reaches the stage 2 temp trigger? idling in traffic on the max temps and depending on stage 2 fan sounds like more wear and tear on the engine and cooling system, so I've decided that i'm going to replace the fan so both stages work.


Thanks

Yes.

Your options for a fix are:

1. Replace the fan (the new fan will have a working resistor)
2. Install a stage 1 bypass resistor
3. Install a wire jumper that causes the fan to always run at high speed (it will also trigger at stage 1 temp). This is the easiest solution if you don't mind the loudness of the high speed fan.

BTW, you're posting in the wrong thread (this is in the R56 2007+ forum). See the other thread for a 2005 model.

Is the R56 resistor on the fan assembly? I have an 08 2door hatch.

The Perfect Solution
 

Hi all, here to revive an old thread for anyone looking for a solution, as I have found a really great one.

As we know, the low speed engine cooling fan resistor fails on the R53 all the time, and there are a few replacements that can be easily spliced into the fan to get around the need for a whole new assembly. Well, I’m here to tell you that the exact same part can be used on the R56 with the same results. The resistor does essentially the same job on both cars, taking a 12 volt signal and cutting it down to spin the fan at a slower speed.

All it takes is removing a few items to gain access to the fan’s resistor and wiring. Remove the intake duct that runs from the driver’s headlight into the air filter box. Remove the bolt from the expansion tank housing and pull it to the side. Undo the turbo outlet hose and tuck it down out of the way. Once the resistor is accessible, pull it out and snip the red power wires as close to the resistor as possible.

The part you’ll be using has plastic molded pieces meant to fit into the R53’s fan shroud assembly. The large rectangular section can be bent and broken off to leave just the resistor and the plate that the wires are soldered onto with a single mounting hole.

You’ll see that there are two thicker red wires joined closely at the resistor, these can be spliced to the thicker red and blue wires on the new resistor. The thinner lone red wires at the fan assembly and new resistor can then be spliced together.

The resistor by nature will get very hot as it does it’s job, and therefore needs the airflow from the fan it activates to cool it. There fan assembly has some frame work close to the motor that works great to run a zip tie or two through to hold it in place so that there is airflow over the resistor. Once secured, button up everything you took apart, and you’re done! You’ll notice the fan will now run at a low, quiet speed whenever the a/c is turned on and the high speed fan will run much less often, creating a more stable engine temperature and a/c output temperature.

See the attached link below for the part.

https://www.minimania.com/part/NME76...UaAtNtEALw_wcB


https://cimg2.ibsrv.net/gimg/www.nor...07938629e.jpeg