um, yeaaaah.

 

It's not setup as a voltage divider, it just looks like that because the picture is so blurry.

 

What do you figure that 'center tap' is for?

Spent a couple hours on the www last night searching - really not a lot of options for replacement out there ...

 

I wouldn't mind a bit expensive (a new fan assembly is over $200) if it were bulletproof. I want one that will last another 10 years.

 

The most bulletproof thing that could be done would be to replicate the resistor with a highly over-specified replacement. Probably mount it to the body metal so that it has a huge structure to dissipate heat into.

The PWM idea is really just a flight of fancy.

I don't think that the fact that the resistor dies is indicative of a problem with the fan motor, it just doesn't have enough of a safety-factor to handle the job it's been given as it is just a ceramic resistor hung out in the air.

Although I haven't seen a measurement of the resistance of the windings, I wouldn't be surprise that the resistor is dissipating as much power as the fan motor in a much smaller surface area.

Anyone want to send me a broken one at my cost for shipping to experiment with? Otherwise I'll probably get to experiment with it eventually on my own.

 

I bought a used fan and my MINI tech replaced a relay and the low-speed sprang to life. I don't htink I have one with a bad resistor or I'd send it to you. When I get around to replacing the fan in my car with the new-relay fan I just mentioned, I'll see if the resistor is bad and maybe send it to you - but that's probably this spring.

 

Just to add my £1 worth................

The low speed fan on my 2003 MCS has also failed but I did not spot it as my power steering pump cooling fan was still coming on when the car got hot and so I heard a fan come on and thought all was OK..........until my heater matrix split.....twice in 6 months.......

Anyway, this is what I recon.

The lowspeed resistor is 0R34 and probably drives the fan at half its full speed, so the fan resistance is probably about 0R34 as well.

Assuming the above gives :-

Low speed circuit, resistor and fan in series.
Voltage 14V, Resistance 0R34+0R34=0R68, so current is 21A. (30A fuse)
Resistor/Fan power =VI =7*21=about 150W as half the voltage gets drops over each resistance.

High speed circuit, just the fan.
Voltage 14V, Resistance 0R34, so current is about 41A. (50A fuse)
Fan power =VI =14*50 = about 576W as now full voltage across fan = lots of noise.

So we need to find a 150W 0R34 Power Resistor...........

I am going to try and short the low speed relay switch earth with the high speed relay switch earth so that both the power steering fan & the cooling fan (fast) both come on at the low temperature setpoint.

Is that a plan ?

 

Heres one :-

http://www.tycoelectronics.com/catal...251,235264&N=7

 

Just a friendly reminder, aftermarket fans (exact replacement) can be bought for less than $100. Also some have a lifetime warrenty. Check e-bay, rockauto, etc. I have one, works great, going on 2 years...think it was 85$ plus shipping....

 

That Tyco link appears to be broken.

 

OK guys & gals,

done some more internet digging..................

It turns out that the Rover 75 which was built @ Oxford just before the 1st generation MINI was, also has the exact same problem with failing cooling fan resistors.

The Rover guys are replacing theirs with a 100W 0R47 (0.47Ohm) Power Resistor supplied by..............................TYCO!

There are even kits on ebay :-

http://cgi.ebay.co.uk/Cooling-Fan-Re...item3efcc1c518

I am going to buy a bare resistor from CPC UK (Farnell) and try and mount it to the BIW (as a heatsink) near connector X53 then plumb it into the fan there.

Watch this space............

 

Not in the UK, they can't. Its dealer or nothing............:(

 

 

Good to see some progress has been mad...after so many false starts and dead ends, it will be nice to see someone sucessfuly find a solution!!

 

Are you saying there are no aftermarket parts suppliers in the E.U.?
American companys may not ship to the UK, but there are various big box auto stores in the UK...heck I watch a show on TV, filmed in the UK, where "modern classics are restored for a profit", auto traders I think. They always are buying stuff from the those places, online, etc, for various cars, including BMW's, classic mini's, Benz's, Porches, Saab's, etc!!

 

Chris.J.Lamb - Great link. That resistor looks exactly like the one I bought from Mouser Electronics, based on post # 51 above. Mine is 100 W, but 0.33 ohms. How did you determine that it should be o.47 ohms?

 

Now I'm confused. That Tyco link above is now working. The resistor it lists is 0.33 ohm but 250 watts. So what do we want? 100W or 250W; 0.33 ohms or 0.47 ohms?

 

The wattage is just how much power it can dissipate, in other words how much juice you can run through it before it fails. Go with the bigger wattage one if price and packaging allows for it.

 

OK.

My math says we need a 150W 0R34 ASSUMING the fan resistance is also 0R34.
This could be right, wrong, way out, stupid, etc. etc.

The higher the wattage the lower the resistor temperature = longer life.

I could not find a 0R34 resistor, 0R33 is close enough.

The Rover boys are using a 100W 0R47 resistor and it works for them. I contacted 2 Ebayers selling the kits and they recon it should also work in the MINI. The 2 cars we designed by very similar engineering teams.............

I have gone ahead and ordered a 100W 0R47 power resistor and I plan to heatsink it to the BIW rather than force air cool it like in the Rovers.

Using a 0R47 resistor instead of a 0R34 resistor WILL reduce the low fan speed but that is better for me than NO fan and bursting heater matrix!!!!

Its up to each owner here to decide, I will post up what I find.......

Cheers

Chris

 

No I am saying that the Fan and Cowl assy is only available from dealers here and costs over £150 and is a PITA to fit.

 

The bottom line is I want a PERMANENT solution. I've bought too many "lifteime warranty" alternators in the past from crappy resellers (PepBoys, AutoZone, Oreilly's, etc) to think they will last. A warranty means ****. I want a LIFETIME FIX, not warranty. For god's sake, it's an electric solid state part (other than the fan) and it shouldn't burn out.

 

If the aftermarket fan has a resistor from a different supplier...which is VERY likely, it most likely will not have the same weak points as the OEM. When they re-designed the fan, I'm sure they did all the same math to find an appropriate component to install.
And the fan is a pain to install (but not super hard...just a bit time consuming.....heck....I did not even remove the radiator supports...just popped out the top two pins, pulled it forward a few inches, pulled the old one out, dropped the new one in....on a S) but it is the same effort to remove and replace the fan as it is to swap out the resistors....fans are motors...brushes do wear....and they get beat to Heck with salt, rain, etc....
I wish you all the best of luck....in 10 years when the aftermarket fans are not available so widely, I'm sure modding will make perfect sense...but spending $50 to fix it is a tuff sell.

Has anybody just bypassed the broken/burnt out part?! It will be loud, but the total power consumption will be the same as if the resistor was there...a free fix, and it will allow the cooling system to function safely without getting close to overheating!! Just a bit more noise!!

 

Would you happen to have some pictures as to how you removed the current fan?
I have a 2003MCS and the Low Speed fan does not work either.

 

Man, I feel your pain.

There was a time when auto parts stores actually sell quality stuff and the sales staff know what the heck they're talking about. In the 80's, there was a handful of independent parts stores and machine shops in my neighborhood. All of them have disappeared once the chain stores popped up and started selling mostly crap. Today even cheap components have LIFETIME warranty because retailers know the majority of consumers don't keep track of their receipts. Thus I only buy from OEM suppliers.

Quality is a losing game when they're all racing to the bottom.

 

+1...

I second his motion.