Yea yea so this has been sparsely posted and talked about, but none of the threads with common issue have been solved.

I have an 02 MCS, suffered from the bad fan resistor deal, replaced the fan assembly about 3-4 weeks ago, car has ran excellent, and is bone stock. I noticed today with about 90 degree ambient heat with the A/C on the light started blinking and the air went warm until I got moving it worked itself out and blew cold air again.

Ok obvious to me, something in the fan system isnt working right? Got home with A/C running, got out noticed the high speed fan is not on, but the P/S fan is WIDE OPEN! Checked the fuse box for blown fan fuses, nothing blown all fuses intact and working properly. Get back in the car, noticed it is starting to heat up so I shut it down.

Let it cool off for about 10-20 min, start it back up without the A/C running and the radiator fan STILL NEVER cuts on neither low or high speed. But with the A/C switch off, the P/S fan is NOT running. When switched back on the P/S fan immediately runs wide open, and keeps running even after car shuts down (for roughly 1-2min).

I assume, and probably correctly, that the P/S fan system is tied into the high speed radiator fan system, if this is the case, can anyone explain to me or point me in the right direction of why the radiator fan is not switching on at all even with the A/C on? Or why the P/S fan runs wide open with the A/C switched on and continues to run after car is shut off?

Just looking for a few pointers here.

Checklist:
All fuses good (including all fan fuses).

Radiator fan is only about 3-4 weeks old, and has been working fine.

Power Steering fan is fully operational (just not sure if operational at the correct time it should be).

Fan assembly does not switch on at all even with A/C on at idle.

 

The problem seems to be consistent with weather, hot weather seems to cause the issue. The high speed fan seems to be inconsistently working when the AC is cut on. In cooler weather the AC and high speed fan runs fine!

 

Blinking light means low refrigerant pressure, doesn't it?

 

I got a similar issue. I installed a new head unit that fried my alternator because of a loose wire. I replaced it and noticed later on that the radiator fan, PSP fan and AC doesn't work anymore. The fuses seems fine ut I can't shake the feeling that its an electrical problem. Any idea?

 

Hi-speed fan is triggered by both your coolant temp sensor & your A/C pressure. If you have a scanguage installed, you can monitor more precisely the temps your thermostat, fans are supposed to function.
-Thermostat opens at 192-198F & is fully open at 217F
-Low Speed on at 221F or when A/C pressure reaches 8bar/116psi, off at 214F
-Hi Speed on at 112C/234F or when A/C pressure reaches 18bar/261psi, off when it drops 4C.
Start w/ checking temp sensor, A/C pressure, fan relay.

 

As far as I know high speed rad fan and PS fan turns on at the same time. Judging from this, PS fan turning on confirms that the there is signal/power going into PS fan. Now you have to confirm if there is power going to the Rad. fan.

Since you checked some of the potential sources of problems, I would check either the relay/solenoid and the fan itself. Sometime electronics seize up when it is out of operating temperature.

Take a multimeter and turn on the AC And see if there is juice going to the radiator fan through the disconnected harness. If power I would shut the engine off at that point and connect the fan and see if it turns after restarting the car. If fan turns two thing can be culprit, fan or the relay.

Relays prone to go bad. You can either use magnetic switch and an LED hooked up to it to check for its operation to see if it is being magnetized or simply replace it and see. Sometime some of these solenoids are interchangeable. Your may pull one of different block say starter relay if the shape and rating is the same you may pull that and use that after starting..

You don't want the wires to be the problem and they rarely are. If so it can be
A pain to trace. But let's worry about that later.

 

Blinking light means low refergirant from what i recall....
wonder if you nicked the ac lines/core when doing the fan.
A system low on refrigerant (r134a, or overfilled with oil) will usually perform ok at lower temps, but fail when the temps and preasures needed go up.....

 

PS
Many folks complain mini does not provide info on how much oil to add when a specfic compotent is replaced....while doing this short cut is common in the indrustry, the only true way to service the system is to evacuate it completely, then refil with a know quanity....
Mini/bmw simply does not provide the info cause they DO NOT DO SHORTCUTS.
also of note...the mini does not use PAG oil in any of the 3 common viscosities, but a differant oil type....since the compressor determines the oil used, using pag is fine if the compressor is changed, cause the compressor maker determines what is approprate for their application.

 

I did not know that they didn't use the common viscosities. Good to know. What do they use? Just so I can learn. TIA.

You can't evacuate oil without major dismanlting, majority of oil doesn't come out when you draw vacuum, if, non at all.

As far as other manufacturers advertising the oil capacity for different components, I wouldn't simply call using that a shortcut but following a guideline as to how much can/should be added.

If componentS have failed and physically leaked oil, where would you possibly begin to gauge how much to add and avoid over or under-fill the system? IE, cracked hoses, condenser, evaporator....

I am not just talking about draining from ONE failed component and measuring oil out of that to replace.

There is a reason for this "common" practice.

I believe the point of the advertised values is to avoid adding too much or too little of oil when components are being replaced without draining the oil out of the whole system (without gutting and undoing connections/breaking seals somehow) and measure to replace it with the correct amount.

If that is the definition of taking short cut, I am sure 99.99% of repairs are done this way and I don't know how Mini would repair their vehicles. I really doubt they are really really draining the oil from system. That is simply just NOT feasible and economically viable to completely drain the system of oil to exact the amount of oil in the system and come out reasonably priced repair.

They may have neglected to research how much oil resides in each component in their AC system and advertise the guideline. I believe that is the ultimate shortcut that Mini/BMW has decided to take.

2cents. :beerchug:

 

This issue turned out to be ANOTHER bad fan assembly! Motor was good, relay bad!