Hi,
My '05 MC is overheating in idle. No problems while im driving. The electric fan seems to be non-functional. I have checked the fuses and looked for blockage on the radiator fan but both of these things are OK.
What do i look for next? how can i troubleshoot this problem?

thanks

 

Well if the fuse is good but the fan motor does not run I would conclude the fan motor Is faulty and needs to be replaced. Keeping cool at speed is likely due to air movement through the radiator.

 

You checked both the fuses under the hood, and by the drivers side wall interior.
if i remember, the underhood fan fuse in the box is not on top, but kinda hidden in the box...make 100% sure you found it and checked it.
No fan indicates the fan may be bad....a multi meter indicating power is getting to the fan to turn it on would second this.....but if no power is getting to the fan....this check would also help you look....

 

TYC brand makes excellent replacement fan assemblies. The one in my 03' failed at about 80K miles.

At the time of my purchase, it was free shipping and life time warranty for $87.00 !! Found it in an ebay store/shop located in GA.

 

Mini while moving, temp guae never varied at all. When idling (w/ac on) it stayed locked for some time, then nearly instantly needle soared...turn off the AC and it quickly retreated. Fan operating as it should.
After watching this nervously for a couple of weeks, I solved when I finally got around to checking the coolant level. Plastic hazy...found it low when I took off the cap. Stupidity only mitigated by decades of driving air-cooled;-)

There is some adage about;"Don't look for zebras first when you hear hoofbeats."

 

First check radiator fluid levels. Mine was low and have since found a tiny intermittent radiator leak that will run low over 12-16 months.

I would start car, turn on AC and see if the fan is moving since it will run at low speed with AC on.

Could just be a simple stuck relay, possibly just mark and switch relays and see if it comes to life if no fan with AC on.

 

The .03 Ohm resistors are know issues no relay. Problem is the are PART of the fan assembly, and unless you are an electronics guru, can find one, and solder it in a new fan assembly is your only choice. I looked into just replacing this part, but when the rest of this plastic fan as some 80K miles on it. I figued I shouldn't be such a cheap bastard...

 

thank you for all answers!

i'm in the norwegian army now, and the pay is very bad (1 $ per hour 24/7). therefore i want to try the cheapest solution first, and that seems to be the relay. my cooper is 2005, where is the fan relay placed? can i substitute the fan relay with another relay that is already in use, just to check if this is the problem? in that case, what relay can i "borrow"?
anything that has to do with the fan relay is interessting information right now..

thanks guys

 

This is where the issue is addressed...

https://www.northamericanmotoring.co...-solution.html

You should find all the info you need there. Also, the bad resistor is often easy to see visually. It is corroded, ugly and obvious. Good luck.

This is a low speed only solution. What I mean is the fan should come on high speed at least for this thread and fix to be correct for you. If the motor in the fan is bad, and it never runs, the fix would be a new fan and fixing the resistor will not work. *Test power to fan to be sure of course.