Hello, I'm new here and new to Mini's. I have a 2004 MC S. As the title states my radiator fan and power steering fan are not working. I found out my power steering fan was seized, I replaced it and I've still got nothing. I've checked fuses and can't seem to figure what the issue is. Any ideas/help? Thank you!

 

There are fuses and relays - at least for the radiator fan. Both high and low fan relays are green plastic blocks in the under-hood fuse box: down the center, next to each other. There's a diagram in the lid, I think.

Have you figured out if your radiator fan only works on high (cycling on and off), or not at all? This is a glaring issue with the Gen 1 Mini Coopers. Low-speed fan circuit should come on as soon as the A/C is turned on, and I have read somewhere that the P/S fan should as well, but not positive about that.

 

I haven't tried relays yet. All fuses looked good. But I did test it with the AC on and neither are kicking on in either low or high speed.

 

Question: how do you know the high-speed fan circuit isn't working? Did the engine get pretty hot and still no fan? Or did you not want to risk it (wisely) and turned if off before anything got overheated? Full 12V (high-speed) goes to the fan when the coolant reaches a certain temp. Coolant temp is the only thing that turns on the high-speed fan. You should make sure there are no air voids in your coolant system as well, as this would give a false reading to your coolant temp sensor (and not trigger the high-speed fan circuit).

It's unlikely that the radiator fan is completely dead, but not out of the question. There's a fan wiring harness connector to the driver's side of the plastic fan enclosure, near the hood latch release lever. You'll see the harness coming from inside the top of the radiator fan housing; 3 wires, thick and thin (brn is ground, IIRC). You should have constant 12V running through the thinner wire (low-speed circuit that runs through the damned resistor) when the A/C is on.

The common problem is that the low-speed circuit is FUBAR'd because of a crappy OEM in-line resistor = no low-speed fan; but yes high-speed fan when the coolant gets hot enough; and then it cools back down and the fan turns completely off, and the cycle continues... I'd offer you the NAM link on this conversation, but you really don't want to read it - it's like over 40 pages or something.

You might try to carefully feed 12V directly to either/both fan wires to see if the fan kicks on or not. Unplug the connector, ground the brown lead, and touch 12V to either other-colored wire. If the fan comes on from either wire, it's fine. If not, yeah the fan is dead. If it comes on from 12V to only one wire, it's a burned resistor and will need replacing. Complete fan replacements are available for under $70.

 

I will definitely try that and see what happens. I already have a brand new fan assembly just because I thought that was my problem at first. And the car did attempt to over heat while I was idling for a period of time talking to friend in a parking lot.

 

There is a single 5 amp fuse under the steering wheel in the fusebox....it us the PS fan...when it blows, it repowers the relay that allows the radiator fan to run.
Look in the car...one of those fuses are bad....
The wiring was changed in 2005, and some cars modified....was to solve this issue.
If the fan is fan is stuck...it will blow that fuse again.

 

Zippy refers to the PS pump fan. Its mounted under the car at the Power Steering pump next to the oil drain plug. It gets gummed up and seizes. When that happens the 5 am fuse blows. In cars with back up sensors, it shares same fuse and back up sensors will stop working if PS fan not functioning. ( sort of a warning system so pump doesn't overheat )

The power steering fan fuse is identified on the chart on the back of the fuse panel...Its the one with the steering wheel image.

 

I'm sure you blew the resistor on the fan. Like filmy said, there is a 40 page thread on the problem.

Put your new fan assembly in and it should work fine. If not, you missed a blown fuse. Check every one under the hood.

When I installed my new fan it still didn't work because the f5 fuse was blown. It goes when the ps fan gets stuck.

And speaking of the ps fan, next time it's seized just clean it out. I need to do mine a few times a year with all the salt they dump on the roads in the winter. Someday I will get one those fan guards. Wonder if you get one when you do the ps pump recall, since they put new fans on.

 

ps: You can check both fans ( PS and Radiator fan ) operation by turning on your A/C. The Radiator fan should come on at low speed, then the PS fan will come on about 30 seconds later. Hard to detect with the sound of the radiator fan running so sometimes requires a visual check to see that its spinning...

 

That's the one fuse I didn't check and had no idea that was for the PS fan. It was blown. I have replaced it, and unfortunately, still nothing. I'm about to give up and let a mechanic shop take care of it. Getting a bit frustrating. Lol... I really appreciate you guys help.

 

If you need a new relay for the Radiator Cooling fan, there are several in the module panel under the bonnet. They share same part number. They are light green in color.

# 61-36-8-373-700 RELAY - $17.99ea.

If the resistor for the Radiator Cooling fan is kaput, then it's time to either replace the entire fan assembly ( if you buy off ebay/Amazon there is a production split in 2003 get OEM Part no, and check sellers data - may save you some time and running around ) or the resistor itself. There is a thread in the forum on that.

You've done the A/C ON test to see if either or both fans are operating correct ?

 

Yes, did the AC test and nothing. Cars temp got to the half way point before I turned it off. And I purchased the radiator fan from Rockauto.com. and PS fan from local part store. I'm about to swap relays with new ones here shortly and see if anything happens then.

 

10-4 ~ keep us posted.

Halfway point is normal. Unfortunately gauge is not accurate. It will either register at bottom mark when cold, half way when normal operating temps are reached, and "Oh **** I just overheated my engine and need a head gasket....".

 

I have a question along these lines. It seems like my PS fan changes pitch when I am doing a slow turn in a parking lot, is that normal? I only ask because I have not heard my low speed fan come on, and once my high speed fan came on as I was walking away from the car in this Atlanta heat. I have coolant in the over flow. 2004 MCS.

 

Well, even after changing relays, still nothin. I'm lost at this point because I have checked every single fuse and relays to those fans and nothing. Only ones I haven't checked are the big fuses under the fuse box that's in the engine bay.

 

The green relays in the fuse box are known to stick, so try tapping on them with something while the system is supposed to be running. See if that kicks on your high-speed fan. Even though you're probably going to be changing out your fan assembly, it would be good to know if that's why the high-speed wasn't functioning.

Enjoy learning "Service Mode."

 

I changed the two relays under the bonnet for low and high speed, and still nothing from either fan. I even plugged in the new fan, and it won't even come on. So something within isn't getting power to the fans.

 

Are you sure the radiator fan isn't seized up itself? Can you reach in there and turn it by hand? Have you tried forcing 12V to the rad fan via the connector I mentioned? Again, unplug the connector, ground the brown wire (pin or hole, I don't recall) on the fan harness side of the connector, and touch 12V to either of the other two wires (I think they're yellow/blu...?) A couple stretches of insulated wire with small alligator clips are your friends here. Also, a bent/folded paper clip pushes into those holes nicely to give you something to contact the 12V wire to.

If you have a lighted circuit tester (the kind with an alligator clip on a wire that leads to a bulb inside a sharp pointed screwdriver-shaped thing), you can see if power is being directed to the fan, when it should be, via that same connector. Just ground the alligator clip on some metal and stab the sharp point into the (fuse box side of the connector) non-brown wire (with the key and A/C on - engine doesn't need to be running). If you get a light from the smaller wire, that means the fuse box is sending power to the fan like it should be, but the fan motor isn't getting it.

If you do this with the engine running and hot, the thicker wire should eventually get 12V (which would mean the fuse box is sending power to the high-speed circuit when it's supposed to) but the fan isn't using it.

Figuring out for sure if the fan is dead will take at least one variable off the table. It's not likely that your fan is completely dead, but if it actually works on both low- and high-speed circuits, replacing it now would be foolish. Plus, you'll know your problem is elsewhere.

ETA: I wrote this while you were responding above. With two known, good relays in the fuse box, I don't know what else to tell you. But before you change out the entire fan, you should at least try to hotwire 12V to it to make sure if it's dead or not.

 

I'm going to try that to see if power is making it to the fan. The radiator fan isn't seized. It speeds freely, on the power steering fan was seized. I freed it up after replacing it with a new one and I did find a 5a fuse that was blown, replaced it and the relays and still nothing. But I will try the light test and 12v test on the fan. But I do know the power steering fan isn't working either. So I'm definitely nothing power from somewhere. Just trying to track that down is a pain.

 

Ok, so I did the 12v test on the Radiator fan and it kicks on... I used a multi meter and checked ohms on the fan, all fuses and relays and they all tested good and showing power is making to them. The radiator fan even tested good before the 12v test... I did test the wiring harness that plugs into the fan and it's showing 94.3 to 94.5? Is that normal or did I do something wrong? I tried switching the ends around and other pin holes on the connector and couldn't get any reading. Could only get 94.x with the brown wire for ground and the pin hole next to it.

 

Cool - good start! Were you able to get the two different fan speeds by touching the two different wires in the fan harness with the 12V? If you only get high-speed (it's pretty loud, so you'll know) but not low-speed, yes your fan resistor is an additional problem and should be replaced - you already have the new fan/resistor assembly to do so.

I'm admittedly terrible with ohm meters, so I can't help you there. But I do know that you should be getting 12V going to the smaller wire while the key and A/C are on, and then 12V to the thicker wire when the coolant gets hot enough. If you get both speeds from the fan, you might have a grounding issue, but at least you don't have to replace it for the time being. Try hot wiring the brown ground wire directly to the frame, plug in the harness and do the KOEO (key on, engine off) test with the A/C turned on. If you get low-speed fan, your harness isn't grounding... somewhere. That may be your only problem.

 

I only got high speed on the fan when I did 12v test. I did the same test on testate on the brand new fan and also only gother high speed. Maybe I did sone thing wrong to test for low speed?... could it possibly be my temperature sensor not working properly to tell the ecu to turn the fan on?

 

Temp sensor failure is possible, but I would think there would be a code thrown for that. Maybe not (?). But this is also why we're trying to take a bad fan assembly out of the equation. It could be a few problems all thrown together.

If you're getting full 12V @ the new fan motor itself (high-speed) then you should also get 12V (minus the 1/3 power drop-off through the resistor) via the thinner wire for low-speed. AFAIK, the two circuits function in exactly the same way, with the same, single grounded fan motor wire. Try again, is all I could say. It's also possible you got a bad resistor with your new fan assembly. If you're feeling adventurous, you could open up the resistor box on the fan assembly and take a closer look, and further touch your 12V hot wire on either side of the resistor (make sure the ground wire is attached to the car frame) and see what you get. In other words, hot wire the fan post-resistor. As long as you don't touch your 12V wire to any ground, there's no danger - but the fan should spark up immediately. At that point, you'd have to trace the smaller fan harness wire back to the connector that didn't work for you.

 

Update:
I gave up on the car and ended up taking it to a repair shop.
Turns out why my fans didn't come on, there is no communication from computer to the fan to turn on the high speed. They did a computer test to turn them on and the PS fan worked but not high speed on radiator fan. They have it down to a wire from the ecu and the fans. They are checking the 2 too see which is the problem and go from there.

 

Damn.

Well I'm not going to argue the findings of a decent repair shop with real diagnostic tools, but it seems unlikely that the fan only spins on low - it's usually the other way around. Let us know what they figure out.