About a week ago, I went to a local MINI shop for an oil change and was told that the low speed on the cooling fan was toast (my car is a 2003 MCS with 117Kmiles). After coming home, I opened the bonnet and watched the engine run for about 10 minutes (the outside temp was around 76), but the fan didn't spin. Then, I switched on the A/C and about 5 seconds later the fan came on and it was rather loud. If I remember correctly, it worked intermittently, but I didn't watch it long enough. I just assumed that the fan was spinning at the high speed with the AC on.

Yesterday, while getting a brake service I also had the cooling fan replaced with a new OEM one since the summer temperatures will require frequent AC use. This morning, I repeated the aforementioned procedure and observed the exact same thing! Needless to say, I'm a bit confused.

Could someone let me know how I can check that the low speed is operating as intended on the new fan?

Thanks!

 

With 76 ambient temp and the A/C on, the low speed should be on. You can't hear it but should be able to see it if you look. If you hear it that is probably the high speed.

With a new OEM fan that works on high, I would check the connectors and also ask why the tech who installed it didn't check it thoroughly before it left the shop.

Rich

 

I could be wrong so anyone correct me if so.....

If I remember this on my R50, the low speed fan is triggered solely by operating temperature. So unless the car gets hot enough it wont kick on.

The AC triggers the high speed fan.

Now a quick test is to use just follow the wires from the fan housing back to the coupler. Disconnect it there. There are 3 wire leads. One for ground and one for low another for high. If you have a voltmeter you can use the 2 leads from that to test the fan. otherwise a couple pieces of wire will do the trick.

Put one lead to ground and short the other from pos on battery to one of the other leads. If the fan works on both of these tests, then the fan works correctly.

 

Thanks for the replies. I did some more testing tonight... After a 15 minutes of spirited driving and further reving up the engine in the driveway, I watched the fan closely and never saw any movement until the high speed kicked in. After 15 seconds or so the fan stopped. Then, I switched the AC on and the high speed kicked in again with its signature loud sound.

I think it's safe to say that I don't have low speed. The tech installed a brand new OEM MINI fan directly removed from its shipping box. Either I'm really unlucky and the new fan is defective, or something else is going on (e.g., connection problem somewhere, etc).

I don't know whether this is related or not, but about 50Kmiles or so ago, I had the power steering fan replaced with an updated version (with the grill and the additional fuse). Since then, whenever the high speed fan is running (with or without AC) and I turn the engine off, for a split second, 5-6 lights come on the dash and it feels like the engine has a delay of a second or 2 to shut down (I hope what I described made some sense). Since I know nothing about the electrical system in the MINI, I have no idea whether these events are related or not. I remember reading that the PS fan circuit has something to the with the cooling fan circuit. I apologize if that's not the case and I confused anyone further.

Thanks again for the replies.

 

I def think your low speed is not working. It should run constantly w/ AC on I think just sitting at idle - something has to draw air across the evap. coil.

 

The fan comes on low speed at 105C (221F) and/or when the a/c is on with a system pressure of at least 8 bar.
It switches off when the coolant temp falls below 101C (214F).
The fan comes on at high speed at 112C (234F), and/or when the a/c system pressure rises above 18 bar,
and switches to low speed when the temp goes down to 108C (227F).

When the low speed fan is toast and the a/c is on, the high speed fan will cycle briefly on and off like you are seeing,
as the system pressure gets above 18 with the high speed fan off and drops below 18 after it runs for a short time.

 

Thanks for the numbers. It turned out that the new fan is working just fine, and what I thought was the high-speed was actually the low-speed. I just assumed -incorrectly- that switching on the AC would automatically trigger the high speed, which is not the case. Through a computer, the tech operated the fan at the low speed, followed by the high speed, and when we switched on the A/C it operated on low speed continuously.

Sorry for the confusion, and thanks again for the clarifications on the numbers.

 

yer very welcome.

 

Hi there all.

I'm a newbe to this Mini lark as I'm a VW head & I desperately need advise.

My new girlfriend's 2001 Cooper boiled up yesterday & has been losing water for about 2-3 weeks but the loss is very irregular & will often be OK for 2-3 days then just drop it out of nothing. I have filled her a 5 litre tub of 50:50 coolant & she has been very diligent on checking (as have I) but yesterday after leaving the car over the weekend she forgot & the inevitable happened - IT BOILED!

I know I should have tracked the leak but the car had a new radiator last year (before I met her) & I just can't see where the water is coming from, as I said it seems very irregular.

I have done my homework & checked the low speed fan operation & it doesn't come on with the a/c at idle so I assume the oh-so-common resistor has gone & I'm interested in doing the d.i.y mod as described earlier in this thread or at least getting stage 2 operation on the stage one circuit for the short term.

I read the thermostat housing is a common source of leaks & this weekend I plan to check all hoses etc.

I'm not entirely ruling out the head gasket but there is no 'Mayo' on the oil cap & the coolant seems clean, a friend who owns a garage is going to do a Hydrocarbon test for me this weekend to either prove or disprove my theory.

So does anyone have any advise/instructions on the resistor mod & any other advise before I tear the thing to bits & do the head gasket???

She has to use the car & yesterday she borrowed mine whilst I checked over hers & topped the coolant up before letting it idle for 20 mins with the heaters on, I then drove it 5-6 miles & everything was fine - no water loss & no boiling. However this morning the water had dropped in the expansion tank by about an 1-2 inches so I topped it up & off she went cautiously & knowing how to drive in preservation mode with 5 lires of coolant & the heaters on max! Currently everything 'seems' ok.........

Help please!

Thanks in advance.

Aaron.

 

Don't forget that the resevoir tank is part of the cooling system in the mini cooper, and NOT an over flow tank. It is under pressure when the car is running. These tanks are horrible and fail very often. The last tank before my current one had a small leak that I couldn't see and my cooling fluid was gone after a day of driving. It steams out of tiny cracks on the tank at different varying temperatures depending on the type of leak.

Also for the fan resistor: it's pretty easy. Just take the front bumper off and get working. I didn't remove the radiator, but rather slide the fan off the radiator's back towards the top with the radiator tilted forward. And I soldered one of the big resistors from mouser directly to new wires that went to the terminals where the old resistor was on the fan (didn't want to alter any of car's wires). I then zippy tied the resistor to one of the arms of the fan (three pieces of plastic that hold the fan motor in the center of the fan unit). It's been 4 years since I did the mod, and it still works perfectly.

 

Actiually, the reservoir tank is an overflow tank on the (regular) MINI Cooper. It is a pressurized part of the cooling system on the MINI Cooper S.

 

Thanks!

So I'm clearer with the resistor mod now & have re-read this thread!..... However, is there a particular polarity to the resistor?

The car hasn't lost any water for three days, however today my girlfriend turned the heaters down & it started to bubble so she switched it off. I'm convinced having a stage one fan again will go some way to curing this once I have nailed the leak & bled it up correctly!

Thanks.

Aaron.

 

Installed the resistor as described earlier in this thread. All splicing done on the fan harness. Worked as described. Total cost under $30.

 

Those of us who are familiar with Ohm's law know that resistors don't have polarity.

 

That was my suspicion, however being a Geography specialist the last Physics lesson I took was in 1999 & my experience with wiring resistors since has been none existent.

Ask once - buy once. Don't ask - buy twice is the law I try to adopt when in unfamiliar automotive teritory.

Aaron

 

Really hope mine works out the same!

The new resistor came today, I checked the input to the existing resistor & there's power in but not out, hoping to get the new one wired in on Sarturday morning.

No water loss in over a week, however the heaters have been constantly on full!

Done hydrocarbon test - came back negative - phew! Whilst there I noticed the radiator cap seal wasn't the best so I fitted a new one yesterday as a precaution.

Fingers crossed!

Aaron.

 

sooo... simply put, If I need to fix my stage 1 fan that isn't turning on, I get the rockauto part.. and install? No worrying about a resistor to unsoldier and soldier back on? And they carry the fans for the 2002 R53's?

Thanks!

 

Whew...read the ENTIRE thing. I'm shopping online now for the best price + shipping for the resistor. Thought my AC clutch was dead too, turns out the relay was kinda popped out of the socket, odd, but yay, AC. Low speed is definitely dead, nothing with AC on and did the wire test, nothing there either (high worked).

I don't have a soldering iron, and while I could buy one, it's something I'd probably never use again, or not for a very long time.

I saw mentions of other ways to get everything connected (shrink tubing, wire terminal connectors, etc), what's the best way w/o soldering or chopping up the wire harness, and is it recommended to do this fix before the plug (engine side) or after the plug (fan side). Planning on making a mount and bolting it to the rad support.

Thanks everyone!

 

My A/C just died today - I'll have to check that relay!

As for connectors, it's worth mentioning that the factory way of getting a new connector attached does not use soldering, but special parts that you crimp on. I learned this when installing the backup light connector on my MINI. So, if you can find good heavy duty crimps connectors from an electronics store it should work well. You will definitely want to protect the connection with shrink wrap and/or friction tape (available at Home Depot). Something like this could work for the crimp connection:

http://www.radioshack.com/product/in...ductId=2103510

Verify that it matches the gauge of wire you're using and can handle the current.

Haven't done the mod, so not sure whether engine side or plug side is what you want. Hopefully someone else chimes in...

Careful with mounting to the rad support - are you talking about the plastic frame that it sits in? Probably not a good location considering how hot the resistor gets. Something aluminum or metal would be better and help dissipate the heat.

 

gknorr, thank you! That's very helpful information! I think I'll do the mod on the fan side, that way it keeps the car side in tact. And if I ever have to replace the fan, it can all come out together.

Those connectors look perfect, I've worked with them before. I'll source some shrink tubing as well, keep it all water proof.

Just ordered my resistor from Mouser last night, should be doing this in a couple weeks.

Thanks everyone! You're part of what makes owning a MINI so great.

 

Such a long thread! I swear I've been reading for an hour, and still haven't found the solution. I do, however, now know more EE stuff than I ever learned in my previous 44 years.

Can someone point me to the Mod solution link/post? Please? I have an '03 MCS that's awfully warm this time of year.

thanx

 

Here is a link.

Chad
Detroit Tuned

 

My 2002 R53 is from 12-2002... I'm just gonna get a new fan from rock, but would you know which fan it is? Two connector? Would anyone know if TYC is better than Dorman?


Looking at this:
TYC Part # 621980 {#17101475577} Radiator/Condenser Dual Fan Assembly
2 Connectors, 1 Large and 1 Small; Radiator and Condenser Cooling Fan Assembly; Single Fan, 2 Connectors

thanks! I got to page 11 and i couldn't read anymore... getting sleeepy...

 

This weekend I replaced the radiator, thermostat & housing, flushed the system & wired in the resisitor.

Result... I now have no loss of coolant along with stage 1 & 2 fans and a happy girlfriend!

Rather than splice into the loom I just cut out the old resistor and wired direct to the tabs.



I didnt like the tacky plastic flange on the bottom of the radiator & was going to machine one from stainless and weld an outlet on but thought this was overkill. So I simply increased the pressure area of the bolt across the flange by using pan washers as the last rad hadn't split, just the plastic flange had warped - this is such a poor design.







This shows where I mounted the resistor using only one screw to minimise damage, I also left as much of the resistor suspended in air as possible to avoid dissipating heat into the body, the resistor is not touching the loom as it appears to in the photo.
The wires were then taped and tie wrapped to the existing fan loom for an almost factory look.

So, total cost... Rad £90, thermostat £10, thermostat housing £29, coolant £10, resistor £3 = £142 plus 5 hours time.

BMW cost... Head gasket £XXX etc etc!

This forum has been an immense help!

Thanks.

Aaron

 

hye there

maybe this one will work
http://www.ebay.com/itm/BMW-Mini-r50...dc13be&vxp=mtr