Sooo....this is probably a common topic but hey, I've done a lot of searching and i've done a lot of helping people out elsewhere so I'm gonna start a new thread. My car is a 2005 MCS with 75k miles. It's been rock solid up until a few thousand miles ago. I have a leaking motor mount too. Yay.

Driving in the rain about a week ago with the AC on I suddenly got the flashing SES light and limp mode. Limped it to work. For the drive home it started right up and drove fine (didn't use AC). Over the next couple of days I experimented with the AC and it worked! Nice and cold. But I was too worried to run it for more than a few minutes.

It's been super hot this summer and I've been noticing the radiator fan running after I shut the car off. Which I guess it should. However, I do not know how long it runs for. I live in the city and don't exactly park near my apartment so it's tough to check.

On this rainy morning I go to start the car and it struggles....and then fails. Doesn't start. Radio is fine, lights work, etc. but doesn't make much of an effort to start. The light on the battery is green. Didn't get a chance to jump it.

So....did the (possibly faulty) low speed fan drain my battery? Is my AC compressor fine but my crank pulley very near death?

Any help would be appreciated. I know I should test my battery but I don't have any tools at my apartment and need to get the car to my brother's house for that stuff.

I have an ATI crank pulley on order since I figure I'm due and I need to replace my belt anyway.

- Andrew

 

It's impossible to say without looking at a few things, but if you jack up the car and remove the right front wheel you should be able to tell if your crank damper is shot - you'll see bits of rubber and you'll be able to see damage to the center rubber part of it. If so, you should stop driving it till you can replace it. Also, if your crank damper is damaged, you'll have overheating, low battery , no A/C and so on.....

 

I'm going to replace the crank pulley and belt soon as I think that's a priority #1 to at least let me drive the car.

Is there a way to check the low and high speed fan for proper functionality? Coolant temps are fine. I might just try to do the resistor fix anyway since I'm going to be in there.

- Andrew

 

Easiest way to see if crank pulley is going is to listen for a slight knocking coming from that side of the motor, or put a flash light on it with the car running and take a look directly at the pulley from the top. If it's starting to fail, you will see it wobbling slightly rather then rotating perfectly.

As for the Low Speed fan, check 2 things, one that the powersteering fan isn't seized and is working (stick something in and make sure the blades move freely). Check the fuse inside the car, should be down near the bottom. For the lowspeed fan, leave the car idle, turn the A/C on and get out real quick. If the A/C is running, the low speed fan should be on at all times. If it's not, then your resistor is probably fried, I just did the new resistor, cost about $35 for the resistor and all supplies, everything works like normal again.

 

So I spoke with Detroit Tuned and have a new hypothesis. They were very helpful.

1. My crank pulley is not actually bad. My newly leaking motor mount dripped fluid onto the belt, causing a belt slip --> limp mode. Maybe. It was also a bit of a monsoon like rainstorm when it happened. Since then I haven't had a limp mode issue.

2. Car not starting is a result of drained battery from the low speed fan issue. I will check it soon (when i have a functioning battery). Do you have a guide for the resistor fix? I'm tempted by the Detroit Tuned resistor kit to make life easier.

Why would a seized power steering fan run my battery?

I'm still going to replace the crank pulley since I need to do the belt and I figure it's going to fail eventually.

Thanks!

EDIT: Also, the light on my battery is still green. Is that thing useless?

- Andrew

 

My battery light was green after I had drained it dead by not closing the hatch. It did take a charge though, and ended up lasting several more years.

 

I was referring to the seized power steering fan because I believe that and the low speed fan run off the same fuse. So if the fan was still working, its more of a way to confirm the low speed is dead.

And the resistor online is super easy. I did it fairly simple. I will try and find the link for you.

 

I actually just bought the detroit tuned fan relay and installed this week as well. I know you can find the same thing cheaper from random websites but its nice to support our vendors plus it helps to have a real life person to call if you have questions or need help.

Anyways, the instructions on the relay are easy to follow. Remove front bumper cover, remove front aluminum bumper/crash support. Remove 2 bolts for a/c condenser. Remove 4 pins for radiator. Disconnect upper radiator hose and tilt it up to prevent coolant loss (only minimal spillage occurs) tilt radiator forward and pull out entire fan assembly. From there you can cut the wires on the old relay and crimp in new wires. You will need 2 10-12 gauge heatshrink crimp connectors and 1 12-14 awg crimp connector which can be bought from napa etc.

Question, you live in a city. There must be an autozone nearby. When your car went in limp mode did you take it to autozone and have them read your fault? Without knowing the p-series fault code anything else is just pure speculation as to what caused it. Also, jump start your car and take it there. They can test your battery for you too. I wouldnt take any repair advise from anyone there though. Just use their free testing service and read your fault from limp mode.

Last, the green light on the battery will remain green despite charge so long as the electrolyte (fluid) level is good. If the electrolyte leaks out or dries up over years then the idiot light will not remain green. Also even though radio and headlights work, cranking an engine takes lots of amperage. So even a slightly weak battery can fail to start a car even though the battery itself might not be bad but just drained a little by that fan staying stuck on.

 

andyroo
An easy way to see if your low/high speed fan is working is to seperate the fan plug located just right of the radiator. On a '05 there should be three wires. One is ground, low speed and high speed. Simply get a 12v supply and using a lead from neg to the ground and then touch the pos to the high speed connection and then the low. If both are working your resistor is fine.
Andy as far as your blown mount goes here is a thread that will give you some options
https://www.northamericanmotoring.co...questions.html
Regards,Steve

 

The light on the battery only tells you it is "SUFFICENTLY CHARGED FOR TESTING".
it does not indicate the battery is good or capable of suppling sufficent power to crank the car...


Your symptoms do not match you theory ....
Failed lowspeed fan will not drain a battery...just allow car to run on the edge of overheating....sometimes kills the ac compressor from dealing with higher operating preassures...
Failed ps pump fan can result in shorterpump life....on a 2005, post jan 2005, it is wired differently with a seperate fuse, and will not stop the rad fan...
Failinf crank pulley will result in odd smells, maybe smoke....very hot running from loss of waterpump, and all other bolton items....
With you miles the pulley might be on its last leg...maybe it did slip...since you have one on order, replace it....and do the engine mount and a new belt....but you MIGHT be just tossing parts at it hopeing to fix it. You might need a pro to look it over if the issues continue...
The bettery should be tested...it might be on its way out also, even if this was one of many 2005 cars that got a new battery in late 2006 under a recal on most 2005 batteries....more than 36 months on the oem battery is borrowed time.

 

A ps pump that is running 24-7 is more common, and will drain the battery fast....a common failure mode...just listen for it....or climb under the car, and verify the fan has stopped, and look at it and listen...you can look for the oil leak too!!

 

Thanks for the feedback everyone! I have an early 2005. Love the car and it's been great up until now.

I guess I misinterpreted the low-speed fan issue. I thought a symptom was the high-speed fan remaining own for too long after the car is turned off? Is that a different problem? Yay MINI....

It very much sounds like the high-speed radiator fan but I didn't think about the PS fan. I haven't noticed any PS issues. My coolant temps have been rock solid through all of this too. I'm getting a jump tomorrow morning so I will figure out what's going on after I park the car at work. I'll also bring some tools to disconnect the battery so I can be sure I'll get home if anything stays on too long...

Maybe my battery is just due and the high-speed fan correctly kicking on after my drive home in the city on a hot day drained what was left? That would be a pretty nice easy fix.

It was time for the supercharger belt and I'm just going to replace the crank pulley while I'm in there. I'm guessing my limp mode situation was likely a completely separate issue to my drained battery problem.

Lots to check tomorrow morning when I get to work!

- Andrew

 

The radiator fan MAY Run a bit on a hot day after you shut the car off...this is normal...if you notice it running more often, check your coolant level. It is possible for a relay to stick, letting the fan run till it kills the battery, but this most likely the least common failure...
on the fan, the low speed resitor that drops the voltage down to allow the fan to run slower fails, so tge fan does not turn on when it is needed by the ac or the car for cooling....till the computer sees a near overheating situation, and turns the fan on high.
This is a loud running fan, and change the idle momentarily when it turns on....alows the rad temps to run very hot, but unless you have a real temp guage on the chro pack or aftermarket, or a scanguage, you will not see it...the regular temp guage is a idiot guage that stays in the middle till seconds before overheating.

 

I have similar issue but can't get a solid diagnosis.

Current issues with 03 MCS with 104k(some of these are probably isolated)
-PS Leak (pump was already replace, hoses are older and probably strectched)

- Rough starts, usually turns, or a turn and then it gives up

- AC is not working, however fan turns on when coolant reaches 234 F as it should
Things I've checked, AC 5 fuse in cabin, AC 30 fuse in engine bay fuse box, checked freeon PSI (thumbs up), check wire connecting to compressor, reconnected, nothing. Volt metered the fuse box for where the AC fuses plug in, getting good reads, it triggers the relay as it should , maybe the relay is bad?

- Door lock actuators no longer work electronically, but the hatch actuator does with the Key FOB and the cabin controls.

- PS fan works , belt seems to be spinning along with compressor pulley.

This car has a crap ton of other minor issues but i listed the ones that may be related.

 

I should have updated this thread. I replaced my battery and all was well. I was expecting it to last more than 75k miles, but apparently that's not too surprising for it to be dead that quick. I think the limp mode I experienced was unrelated, with the AC on in that horrible downpour I think my belt just slipped or something.

I replaced my belt since it was due and did the ATI crank pulley at the same time, just because.

- Andy