Where is the air conditioning compressor relay for the base 2008 mini? The cover in the engine bay doesn't have one specified for the AC.

TIA

 

I've never had a reason to look for that relay but (according to Bentley) it's located in the fuse panel in the right foot well. Apparently, it's located on the BACK of that fuse panel circuit board and Bentley calls it a "soldered" relay. You'll have to remove the entire kick panel (not just the little access door) to gain access. I've removed the kick panel once before (it wasn't too difficult) but not the fuse panel circuit board. Bentley calls it "K19". Good luck.

 

Thanks Dave, now they've got me wondering about the design change from the R53 & why it needs to be soldered in. Sure makes diagnostics more difficult. Guess I'll take a different path - purhaps checking the compressor coil via the compressor connector.

 

I'm no AC expert but I think I'd start by verifying that voltage is actually getting to the AC compressor clutch and go from there.

 

Dave, yes I did check that as well. I've found that the coil appears to be within the correct range, however I'm not getting any voltage to the compressor's harness-side connector. The two A/C fuses I could identify in the passenger compartment panel are good. There don't appear to be any A/C fuses in the engine compartment fuse panel -based on the cover's info.

So next is to locate the low-pressure switch - as I believe it would have a cut-off for the compressor. Other possibilities are the A/C dash switch and the relay you mentioned - but I'll save tearing apart the dash & panel for last.

 

Might be as simple as low refrigerant. Good Luck.

 

dave, already tested that. The low side had excessive pressure - which is what lead me to the compressor. Since clutch is not engaging I can't get an accurate reading on coolant level. It was working great - and just quit. So hopefully its just wiring issue.

Anyone have a simple schematic of the R56 A/C system?

Edit: Thought I found something on BMW-Planet - but guess what - the pages I was looking for had bad links -bummer.

 

My compressor is no longer working either; '10 w/ 50k miles. It quit on me yesterday. At first, A/C operation was inconsistent. It only seemed to engage for two or three second intervals, and was blowing cold air intermittently. Then, it decided it would only engage when I was decelerating, short blasts of cold air. Now, nothing at all. No compressor drag on the engine, no clutch engagement noise, nothing.
I suspect a failed compressor. Based on what I have turned up via Google searches, it looks like these commonly fail between 50k and 60k miles. That honestly would not surprise me either, given the sort operational life of the majority of the components on Minis.

 

dude, one thing to consider when looking at a failed compressor is to verify whether or not its the clutch coil that failed and not the compressor itself. All my research indicates the coil is the vulnerable part - especially at the low mileage you're describing.

Good luck.

 

Finally had a chance to get under the hood this weekend. It looks like I have a small coolant leak of unknown origin, which may or may not be related to the a/c being non-op. Local dealer can't get me in until June 16th. When it rains, it pours.

 

Upon further investigation, I located a small crack in the thermostat housing. I'm guessing my thermostat failed due to the leak, or vice verse, and my car won't allow the a/c to run until that issue is resolved. I'll be replacing that myself, and will post results in this thread.

 

Replaced the thermostat housing, flushed the antifreeze, refilled with genuine Mini antifreeze diluted 50/50 with distilled water, bled the system of air. On the initial test drive the a/c functioned for about five minutes, but has stopped again. I went back through the entire cooling system again looking for leaks, but can find nothing. I still suspect the a/c malfunctioning is related to the cooling system, but don't know where to go from here.

 

Side note; the thermostat I ordered from ECS runs 5 degrees hotter than my OEM thermostat did. 225 F vs 220 F. I doubt this has anything to do with the a/c not working, as it doesn't work at any temperature, even on cold starts, but thought it worth noting.

 

dude,

Bummer. It sounds like you did all the right things - but it doesn't get the results expected. BTDT.

Got our mini over to the dealer for diagnoses. The compressor works when powered directly. They've traced the loss of power to the Fuse Box SPEG High (or FBE) located in the passenger side kick panel. I'll be pulling that soon to check for any obvious connection issues before attempting to replace it.

 

Well I finally got some time to dig into the kick panel to remove the FBE. I wanted to inspect it first before ordering a new one. Unfortunately there wasn't anything obviously wrong - like a loose/bent connector pin or loose component. SO I'm off to order a new one.

Here's the link to removal/install instructions I posted. Once I get the new one in I'll post results.

 

Im trying to diagnose my AC as well. According to this nice websitehttp://www.aa1car.com/library/ac_no_cooling.htm I should have 170-250 psi on the high side port on a 90 degree day.I have 100. And 95psi on the low pressure port. This is with engine on AND engine off.

What values did you find to be correct for an r56 cooper S. I cannot find values in the Bentley manual or on ALLDATA.

When i press the AC button, the green light comes on, engine idle changes but I dont hear the compressor clutch engage. (my 2008 has 140k miles). 3 weeks ago when I last used the car the clutch came on but air was barely above ambient. Now, no clutch engagement.

What pressure values are correct?

Thanks!

 

I was wondering about that too! Thanks for the answers all. I suppose you cant test that relay given it is permanently affixed?

 

Hey guys,

I was hoping you could give me some tips on diagnosis.

So the AC stopped working on my 2008 S. 142k miles. The clutch does not turn when the AC button is engaged. Idle does change when I ask for AC and green light comes on.

I check and the AC compressor is not turning but I backprobed the compressor electrical connector and it does get 14+ volts when the AC button is on, (and nothing when AC off) so the compressor is getting voltage.

Does this necessarily mean the clutches or compressor is bad? I assume that if 14 volts are making it to the compressor, all other system are ok, no?

This video corroborates
The low pressure and high pressure sides of the AC are reading 75 psi with engine off and engine on. Thats way too high for the LOW side and very low for the high side. But according to this video, that static pressure on the low side isnt abnormal.


I backprobed the AC pressure sensor switch (which is near the power steering connectors near the back firewall driver's side) at red with black and then red with yellow wires and got continuity which implies there is enough coolant pressure to give the system the green light to turn on....I suppose. (this is with engine off)

Any help would be appreciated. Bentley manual is worthless on this issue.

 

Ive had the AC compressor plug connector go funky it was a plastic I've not seen before yellow and had turned brittle and the pins inside were not connecting. I just cut it out and wired it together AC works again.

 

No kidding...thats nuts. I guess I could jump the compressor as well. Thanks for your thoughts.

 

Euler,

I started back probing the compressor side of that connector and as I start moving the connector around, the son of a ***** clutch starts engaging! As I pressed the wires into the connector on the compressor side the clutch engaged and disengaged.

This connection is faulty.

Thanks bro!!!

Update:

Ok so here is what backprobing is in case you dont know:



On the harness-side of the AC compressor connector as seen above I was getting 14.7 volts with engine running and AC on. Then thanks to Euler, I checked the voltage on the other side of the connector (compressor side) and wasnt getting any voltage but as I moved the connector around to get a better angle for the probes, the AC clutches started engaging and disengaging. I've messed with electrical harnesses before, so I know they can go bad and can be repaired. BTW the dealer had broken the connector where it attaches to the metal bracket at some point and ziptied it in place. I dont know if maybe they had pulled on the connector wires and damaged the connector. Person I bought the car from was loyal to the dealer. But I digress..

When I disconnected the two halves of the connector I noticed one of the pins was sticking out half as far. You can see that here:


So I took the back of the compressor-side connector off and that pin pulled out easily. Too easily.



The red wire and pin wouldn't budge. Nice and tight. So I pushed the green pin back all the way through and glued it in place so it wouldn't back out. Hopefully that will do the trick. I also brushed a little DEOXIT to the pins and pin receivers to make sure there was no oxidation. DEOXIT has saved my butt on more than one occasion with some serious harness issues on another car.

I wonder how many guys put in new compressors thinking they had a bad clutch when in reality they only had a bad connection.

I also had to add 12 oz of r134a. But that's another issue.

Ill let you know if any thing else comes up.

 

The Yellow plastic I had broke apart while I was inspecting it once I had it out, it was very brittle. Ive seen blue, black, white, red, but never this yellow that I can recall. Also I think there was a black outer jacket. Great photos I'm sorry I did not take any, I always mean to. There are plenty of simple connectors that could replace this and if you are planning a trip it might be a good idea its not hard in the garage but on the road it can be a bit difficult.

 

Yellow is definitely a new color to me as well. Id rather not sacrifice the the harness side connector which is in good condition. Hopefully the glue will stop the pin from backing out.

Plus its not easy to solder properly on your back with such a short section of wire.

Ill keep ya posted. Thanks man...I appreciate your assistance. This forum is definitely light on tech support compared to other car make forums.

 

Lex, glad you got it resolved. Thought I would note here that in addition to the AC relay, noted previously in side panel, the fan relay appears to affect the AC clutch's ability to engage. I had issues with my fan running for extended periods & pulling the relay also disabled the AC. I can't verify this without schematics - but seems reasonable since fan is forced on when AC is activated. No fan, no AC.

I traced the fan issue to a small coolant leak that was causing the level to drop over long periods and the coolant sensor would read air (too high a temp) and run the fan to the point of draining the battery. Once coolant issue was resolved this corrected fan issue. However, the relay needed replacing. Be sure to get correct one from dealer as after-market didn't allow AC to work. Replaced with dealer fan relay and AC issues resolved as well.

Regards

 

Yes this is what Ive learned as well. If AC fan doesnt send signal, the AC compressor wont engage because the condenser would be be cooled if the car was not moving.

What do you mean the coolant sensor would read too high a temp? The AC fan would stay on with the car off and drain the battery?