Wow. This may be the thread that never dies! I mean, as long as there are R50s out there, there will be this problem. AAARRRGH!

Is there any way to actually FIX the problem instead of patching it? I mean, are we certain the resistor fails due to heat? There has been some speculation that the bearings start to go and places more of a current draw that might burn up the resistor. Replacing a resistor in that instance would just prolong the problem but not fix it permanently.

I know there are electric fans out there that don't need replacing after 100k mi. Can't we get one of those going?

 

There is probably some aftermarket fan/motor which will fit in the stock location. But... those fans cost more than the aftermarket "OEM-style" fan assembly (which includes the fabled resistor) and you still would need a resistor for the low-speed.

The fact that the fan(s) work on high-speed shows that the fan itself isn't the problem. It seems more like the resistor isn't suited for the application - plus, it's not exactly mounted in a decent airflow/cooling location.

I can see how the inline resistor fix is one solution. But when replacing the entire fan/resistor assembly costs $80 and takes only 1 hour of time (even for a novice), I felt it was best to stay with the factory setup. If my new fan/resistor dies within a couple of years, I may go the band-aid resistor route instead of replacing the fan again.

 

And from the inventor of the solution......

The reason I think that the resistor is the peoblem is due to the history of the design of the system.
It is based on the Rover 75 (R40) design from the same engineering team based at GDEC in Gaydon. The Rover 75 has the SAME problem and basically the SAME resistor.

The reason I came up with the external resistor fix was my R53 is my dailey drive, I still use it to get to work EVERY weekday and so at the time I could not afford it to be off the road and due to a new baby had no time to fix it propoerley at the weekend.

My solution allowed me to fit the resistor to my car in the car park at work over a number of lunchtime breaks................luckily my boss never twigged this.

The only real permanent fix is to replace the whole fan resistor assembly with a new OE one........with all its related shortcomings........

 

For those of us keeping current on this thread...

Update/edit: after replacing my entire fan assembly, the low speed radiator fan does come on when the A/C is switched on as it's supposed to. However, my power steering fan did not come on with the low-speed rad fan. I could turn the fan blades with a screwdriver, so I knew it wasn't bound up. I removed the P/S fan and hotwired it - and it does work!

I'll have to do more research as to when the P/S fan is supposed to come on. It would make sense that it only comes on with the high-speed radiator fan circuit. Or perhaps it does come on with the low-speed fan if the low-speed fan is triggered with temperature as opposed to the A/C switch.

Anybody know for sure? And if there's a relay to replace for just the P/S fan?

 

According to the posted schematics on bmw-planet:

Up to 12/2002 - the PS (power steering) fan comes on when the high-speed EC (engine cooling) fan comes on. Further, there is no interceding relay. If the HS fan comes on then the PS fan should be on.

Later minis - The power steering fan comes on with the low-speed EC fan, however there is an interceding relay. This relay switches power only to the PS fan and its switching coil is powered when the low-speed EC fan turns on - so two points of relay failure there. However, if your mini is in this age category, if your low-speed EC fan is running and your PS fan is not (but you know it to be good), under low-speed EC fan-ON conditions I would check the motor's ground connection, the switching integrity of relay KB69923 and/or fuse F41, the fuse and relay that control and provide power to the PS fan.

 

I recently did a 60,000 mile service on my '04S and while it was on the jack stands I ran the engine to check for oil leaks and power steering leaks (I removed the pump and cleaned out the motor end of graphite dust). While the engine was running I turned on the AC and after a half minute or so the radiator fan began cycling on and off. I had previously installed the external resistor fix since my fan was not working on low speed when I bought my car (October 2010).

While under the car checking for leaks, I watched as the power steering fan cycled on and off with the radiator fan. The engine was still cold so this was strictly an air conditioning-driven fan situation.

Eric

 

Well crew,

I'm totally confused and more than a little discouraged. First, Filmy, I received the Dorman aftermarket fan and housing just this past week. As you had promised, switching old from new wasn't more than a one-hour job and I've only managed to lose a little radiator fluid (mine was, I'm surprised to report, the BMW-spec "blue"). I did note (pictures to follow in another post) that the flat wire wrapped around the ceramic cylinder was bare and obviously oxidized. The green ceramic(?) coating covering the new resistor was completely worn off of the old resistor. I'm hoping that this "paint" makes a difference. I've switched fan housings and replenished, and bled, the radiator coolant, but I have yet to test my work. I've found that many of the radiator fins above the under-bumper and the air-conditioning coil fins below the same under-bumper have taken a pounding. I plan to set my iPod to shuffle tomorrow and to spend some nerdily obsessive time doing my best to straighten and clean these fins before testing for low-speed ECF/PS cooling function. Also, two of the three 10mm bolts that join the plastic bumper cover valence to the splash shield stripped while I was removing the bumper cover. I've got to devise some method to join these parts securely to one another. Thank goodness for electrical zip-ties!

Anyway, tomorrow I mean to straighten those beat-up fins and check for PS cooling fan function. I've also just received delivery of the steering spindle and the much-needed Bentley Mini service manual. After I've verified (hopefully) that the fan housing replacement didn't introduce any new problems, I'll get started on the steering spindle. I had so many fun "mods" planned for my Mini this Spring and I've eaten up the fun budget just trying to get him back on the road!

 

There's a "comb" tool available at most auto parts stores for radiator fin straightening. Makes it much easier than one-by-one...

GL on the steering spindle!

 

Filmy, thanks for the tip regarding the radiator fin comb. Though I was unable to find one locally last weekend, I appreciate your suggestion. I made due with a small-blade screw driver and did my best to repair the most damaged sections of the radiator and air conditioning coils.

So, the fan replacement went well and relatively easily, but seems to have changed nothing. I noted that the resistor on the old housing seemed pretty spent and had my hopes up, but I now realize (nod to Bradley99 for pointing this out to me earlier) that I've been looking at the low-speed ECF and not the high-speed fan. Again, with the engine idling and warm AND the AC cranking, I have yet to see the PS pump cooling fan spin. As it isn't spinning--if it's supposed to be--it may be down to a relay. I've been replacing parts at such a fevered and expensive pace lately that I'm just not ready to buy a relay based on a hunch.

The lower steering column replacement went pretty smoothly, too. We all know how ridiculously tight the work spaces are on these cars are and even with the front end on two jack stands as high as I dared lift it, there wasn't a lot of room for leverage, fingers, and tools. The worst part of this job was freeing the lower u-joint from the steering rack pinion. The pinch bolt came out easily, but the joint bracket itself was gritty with rust and didn't want to let go. I did manage it, though, and disconnecting the upper u-joint under the steering wheel was very easy. I'd locked the steering before lifting the car so as not to inadvertently turn the steering wheel and I took care while under the car not to move the passenger side tire (the driver's side tire and wheel well liner were already removed) or the pinion of the steering rack. As soon as I had the old lower column out of the car and in my hands I knew that this had been at least part of the steering problems I've been experiencing; the lowest "knuckle" of the lower u-joint was very rusty and almost seized. It could be moved (with a lot of force) but it wasn't nearly as free and smooth as the knuckle on the new part. Replacement with the new lower column was really a breeze (thank you, ECSTuning!). I got the car back together and lowered onto the garage floor as quickly as I could. A test drive confirmed that the "sticky" and intermittent steering problems were a thing of the past. In spite of all the parts I've replaced, I'm now all but certain that if I had replaced only the power steering pump and the lower column I'd have been alright. Still, it doesn't hurt to have a new ECF housing and PS pump cooling fan (with a proper debris guard).

I could post pictures of the PS pump/fan replacement if that will help anyone facing a similar repair, but I didn't take pictures of the ECF or lower steering column replacement procedures--I'd found lots of helpful text hints and tips in this thread. I'm just relieved not to have to think about this for a while and it's good to know that my wife's car is now safe for her to drive. If I feel like revisiting my obsession, I may take the car to our local BMW mechanic and see what he has to say about the PS pump cooling fan (when it should come on, etc.).

Thanks to all on this thread for the help and kind wishes. I hope my "chronicle" might help someone else who's experiencing trouble with their steering.

 

 

MINI33342, not sure if the popcorn-munchin' emoticon signifies interest in this "endless" thread or simply amusement, but I thought I'd offer yet another follow-up.

My steering is now working properly and I'm still convinced that if I had only changed the PS pump and lower steering column, I'd have been fine. Still, I won't truly put this issue behind me until I have some way of testing the PS pump cooling fan. So, my local BMW mechanic is going to put the diagnostic tool on my Mini to verify fan function. He tells me that the PS pump cooling fan really shouldn't have to come on unless a few conditions are met: 1) it's a very hot day, 2) the engine is warm and the AC's on, 3) I'm stuck in stop-and-go traffic OR I'm parallel parking and turning the steering wheel to extremes to do so. I take this to suggest that the PS pump must be fairly rugged. This mechanic also mentioned that he's swapping out the lower steering column on BMWs, Saabs, and Volvos all the time. That lower u-joint is very weather-vulnerable.

 

Just found this thread and wanted to stay on top of the posts.

Lots of great info.

 

How did you guys solder the resistor wires to area where the old was? I've tried my radioshack rosin and flux, but they just won't stick. I've also tried a standard 20 watt and 40 watt iron, no good. Any help would be appreciated and thanks for all the info and work.

 

I think the original is welded. The modifications I've seen discussed have put the surrogate resistor further up the chain - in the wires that power the resistor/fan.

 

The resistor is absolutely welded. I thought for a bit about punching holes in the tabs and mechanically attaching the wires where the resister was and mounting the resister somewhere on the fan shroud. But the beauty of this fix is that you don't have to take the fan assembly out. Once it is out, my feeling is a new assembly is the best choice. But if you have one of the cars there the external resistor can be put in before the assembly connector, that is preferable as it is quick, easy and will likely last a long time as the fans themselves seem not to fail. Also on the units that take to the external resistors the relay is also external. On the early ones, 2002 -2003, the relay is also prone to fail and cannot be changed without taking out the assembly.

Rich

 

For what itis worth, I have exchanged the ceramic low-speed resistor with an aluminum heat sink cased resistor from a 5-series BMW . I got the resistor at the U-Pull yard and cut it out with 5" to 6" of wire on either end. I crimped/soldered small ring ends on both ends of the "new" resistor, and drilled out the spotwelds from the original ceramic resistor and mechanically attached it with a 8-32 screws and nuts. I mounted the resistor externally on the plastic housing where it wiould get some airlfow.
It runs on low speed just a little faster than origimal, and high speed works as it always did. I've had this arrangement for about 9 months now with no problems. Everything works like it should, and that piece of ***** green ceramic resistor is gone forever. By the way, I have replaced the fan assembly twice with OEM replacements, only to have them last a little more than a year each.

 

This is a great alternative solution. Can you tell us exactly what year model or chassis designation (E-number) 5-series you found? Any rating numbers on it?

While I'm happy with my new assembly, I'm aware that something may well go wrong with it at any time.

 

Only a little more than a year each??? Why use OEM when it doesn't last like.... say 10 years or more?

My cheaper, Mexican built VW New Beetle's 2 radiator fans and related electronic sensors are still good (knock on wood) after 10 years and 186,000 miles.

 

OEM doesn't last either and it's 3X more expensive, not to mention the dealer install, if chosen, is another $300. And the great majority of Mini owners can't do the repair themselves. Unfortunately, they just know "radiator fan went out - gonna cost $$$ to fix." If most of them knew the "fix" could be a simple $9 resistor (which could have been improved upon from the manufacturer) they'd be in a tizzy.

It's really a design flaw. The resistor is the weak link in the system and having placed it where it won't get much (if any) air flow to cool it - it's bound to fail. And why would they improve the design (better resistor, etc) when owners are forced to pay for parts and labor, creating profit for the entire industry?

This is the world we live in today, sadly.

(Sorry. I'm in my cynical mood today. )

 

Uh... Filmy -

I think you may have misread my post. I'm AGAINST using OEM for the exact reason you've stated. Besides, it's not the fan but the POS resistor that fails.

You're right about BMW/Mini not improving the components when they really know it's a flawed design... more profit for them.

Cynicism... you're not cynical, you simply have experience!!!

 

blueflash;
Excellent fix, just what I was thinking, couldn’t understand tapping into wiring or bridging high and low speed leads. None of the pictures actually show where the resistor leads go. But your solution I understand.
Thanks

 

Well, extreme weather in the Northeast has actually affected the diagnostic tests my mechanic was going to run on my Mini today. Severe thunderstorms in our area have him concerned about hooking the car up to the server in Germany for any length of time. With all that I've been through on this car lately, I decided not to press my luck and set up another appointment two weeks from now. So, I STILL can't confirm that the power steering pump cooling fan kicks on when it should, but I have had absolutely no trouble with the steering since replacing the lower steering column. If I ever do conclusively discover whether or not the PS pump fan is working, I'll post yet another update.

 

So after days of examining, guessing and reading the forums, I have determined this to be the root of my issues. I had a couple questions I hoped someone with more knowledge than myself could weigh in on. With temps in the upper 90s in St Louis and no AC, I want to act quickly, so any info would be welcome.

1) It would seem like there would be a way to bypass the existing temp-determined fan speed. Couldn't a person just hard wire the fan to turn on with the ignition or even by switch to just run at the higher speed continuously? Other than potentially shortening the fan's usable life (which, considering it's already damaged, isn't a deal-breaker), would it have inherent problems, or be a terrible idea?

2) I've been customizing cars a long time now (relative to my age), and I've ALWAYS viewed the failure of an OEM part as a chance to upgrade. It sounds, though, that most opt to modify the stock part to function as designed once again, or replace it with an OEM or OEM-cloned part. Is there a reason not to drop in a Misimoto or SPAL fan?

3) I can figure out an aftermarket setup, but if anyone has gone more performance minded, are there any full mini-specific setups? If not what'd you use?

Thanks guys. Any input is appreciated.

 

In most cases, the fan is not the problem - the resistor for the low-speed circuit is the problem. Changing out the fan to another brand would be redundant under that circumstance.

Sure, you could hot wire the fan to come on with the key, or with the A/C on. But... when driving down the road, you really don't need your fan at all so you'd be wasting energy and tiring out the fan prematurely. The airflow through the front of the car (condenser/radiator) will suffice. Secondly, the high-speed fan is NOISY and vibrates a lot - you don't want that.

The true fix is relatively simple. Either you wire in another (correctly rated) resistor in the circuit (as shown in an earlier post) or you replace the entire fan/resistor assembly (takes about two hours and $80.)

My advice is: don't try to reinvent the wheel here.

 

I've got to agree with Filmy on this. In fact, following his example, I installed the Dorman radiator cooling fan in my '02 Base ($80 for parts, about 1 hour my labor) and the new fan is quiet and stable. As I mentioned in this thread, I still haven't confirmed that the power steering pump cooling fan is switching on per design, but I'm going to have that tested as soon as schedule and weather allow. I don't know whether or not you're considering replacing the radiator fan or the PS pump fan, but for what it's worth, the PS pump cooling fan I did install came from SteeringPumps.com. It's actually a SPAL and cost around $120 (I think). The stamped stainless steel protective grille I bought for it from Outmotoring.com will, hopefully, do a better job guarding against debris than the minimalist plastic OEM grille.