The suck relay and the resistor problem are two separate issues, you only need to do the resistor mod when the fan does not go onto low speed
and goes straight onto high (loud roar) when the aircon is on even if the engine is cold.

 

So from what I am describing, I only need to do the resistor mod??

Thanks,
Mark

 

If your fan gets stuck on and wont switch off, its the relay
If your fan goes on to full speed and pulses on and off on a cold engine with AC on its the resistor.

 

And what if the fan and resistor are good (new) and still no AC compressor or low speed fan? Fuses all check as well.

 

If the fan is dead? Will the resistor kit that available can make the fan alive again?

 

No...

 

I have read thru a number of posts, but not 100% sure how the fan is supposed to work when everything is normal. Does the fan run at low speed whenever the engine is on? Or is it controlled by temperature even for low speed.

This is my situation - I do not drive my car daily, but did notice the last couple of times that I pulled in the garage, the high speed fan was on and stayed on for awhile after turning the engine off. I thought it seemed a bit unusual given it is still winter, but did not think much about it. This past Friday, got caught in a traffic jam and temp spiked hot and red temp light came on. I pulled over to the side of the road, turned the car off. Car had water, no steam, no odor. After 5 mins, fired back up, temp is normal. When I got back into the traffic jam, I made sure my a/c was running as I assumed this would force the fan on. Temp would fluctuate rapidly between hot and normal and I could never detect a pattern. When ultimately out of the traffic jam, back to speed, the temp remained normal (and I was on a trip - never acted up again).

Found this thread when I returned and I am curious about the low speed fan problem - if the fan does not run at low speed, can the car get hot before the high speed kicks in? Maybe my description is more like a thermostat problem. Thanks for suggestions (btw, car is MCS '05).

--travis

 

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).

 

from here :-

http://www.bmw-planet.com/lib/mini/E...20OVERVIEW.pdf

Engine Coolant Fan

The Engine Coolant Fan is controlled by the EMS2000 through a relay and relay pack at two different speeds,
Low and High.
In addition to maintaining coolant temperature, the fan is used to cool the A/C refrigerant and where applicable,
the ECVT gearbox oil.
The cooling fan operates on Low speed when the AC is switched on and the system pressure reaches 8 bar (116
psi). Should the AC system pressure rise above 18 bar (261psi), the fan will automatically run on High speed.
For the engine coolant system the fan operates on Low speed at 105°C (221°F). When the temperature drops to
101°C (214°F) the fan will switch off. High speed is switched on at 112°C (234°F) and will remain on until the
system coolant temperature drops by 4°C (39°F) at which point the system will revert to Low speed fan.
The engine coolant fan is operated through two relays, a Low speed relay and a High speed relay. The Low
speed relay is mounted in the engine compartment fusebox and is energized any time fan operation is needed
(Both Low and High speed). The High speed relay is mounted on the fan housing in the relay pack. The relay

 

^ Just one note -- it only needs a 7.2°F drop, not a 39°F drop to turn revert back to low :p

 

Hey all.
I am planning to perform installing a resistor so I can get my damn AC back for the summer

Anyways, I was wondering what kind of 12 gauge wire that I can use ?

Would this wire from radioshack work?

http://www.radioshack.com/product/in...Value=12+gauge

Also, excuse me for being an electrical noob but do you just wind up the wires on to each ends of the resistor and wrap it with electrical tapes to secure them?

Help a noobie out to get some coool air back please!

 

I noticed that too - whoever wrote the original text confused a 4C drop (= 7.2F) with a 4C temperature, which converts to 39F.

 

The resistor mod won't fix your broken A/C, it just gives you a low speed fan if it is stuck on fast. No wrapping the wire is no good it has to be soldered.

 

I have not read thru this whole thread, but if anyone is looking for a resistor kit for there low speed cooling fan, this is great kit. Fan Relay Kit.

Chad
Detroit Tuned

 

You can buy a complete fan assemply with relay, resistors and fan with exact factory shroud from O'rilleys for $115.00

 

Chad at Detroit Tuned has an off-board resistor to fix it.

http://www.detroittuned.com/shop/?productID=530

OK, if I had scrolled up, I would have seen Chad had already posted.

 

Just replaced mine... pretty quick and easy actually!

 

If you've caught my other posts recently you would know about the issue my mini is recovering from regarding a .45 bullet and my thuroughly thrashed intercooler. Good stuff, right? So my new IC is about to go in and end weeks of maintenance and cleanup from my car's gunshot wound. It's been a nightmare. You wanna talk about throwing codes? Anyway, while its [still] apart I hoped to address my fan issue too as St. Louis has already topped 90 a few times this year. But after a dozen all-nighters and basically replacing the entire vaccuum system, IC, IC boots, and whatever else, I've had it - and so has my wallet. All that said this question mostly stems from laziness and frustration. Can I; and if not why, just hardwire the fan to run when the engine runs? I mean what's the harm in just running it at high speed all the time? OR wiring it to the AC on/off switch - or an aftermarket switch so that I can override the setup and turn it on if I want aircon-leaving it to operate autonomously otherwise? Or why not just dump the fan and toss in an FAL slimline attached to a switch, the ignition, or even a standalone temp sensor?

 

Get the dorman one from rock auto and spend the 45 minutes and fix it. Doing anything else only saves the 100 bucks and is not really kosher. I know you have been throu a lot, but don't waste your time on cutting corners.

 

Consider reading my DIY on this...

 

Yes do it properly!

 

Can anyone confirm the value / type of the diode that is used inline.

I have a 2005 MCS with the single wiring harness plug & am about to replace the resistor without removing the fan assembly & would like to add the diode into the system.

 

I don't think the item has been confirmed as a diode, and maybe a thermal fuse

 

Does the Dorman part have to be installed in place of the original in the fan unit, or can it be wired in at the harness?

 

you have to remove the fan and wire it in at the fan. there is a Diode that breaks or burns out in the old unit. but they call it a relay kit cause it makes the relay work, even tho it's not a relay, depending on a one wire or two wire.