Hey guys,
My wife owns a 2003 mini cooper s that now has an inoperative a/c system. I haven't had time to really get serious about the diagnostics of the car but wanted to get some insight on here about known problems.

Background on the car...

About 2 months ago my wife complained that the cooling fans seemed to be louder than normal and was staying on longer (high speed staying on at times). I did some searching on here and found that there are some known issues with the cooling fans losing their low speed ability due to a failed resistor. Our recent move, long job hours, and other "complications" did not allow time to repair the mini. Yesterday she let me know that the A/C now stopped working and the fan noise stopped. Being that my wife drive in LA traffic, the a/c being inoperative is not making her a happy camper... BAD HUSBAND (Me).

After looking at the car tonight briefly the low and high speed fans are defnitely inop. I also verified that the coolant level is good and the vehicle does not seem to overheat (at least not yet). I've read several of the fan related threads but didn't see any complaints that the a/c stopped working...

Does the ECM pickup the fact that the fans are inop and so the a/c has now been de-activated (through the high pressure switch)?

Have any of you seen vehicles that lost the high speed fan as well?

Any other ideas?

My tool box won't be shipped from my old address till next week and then it'll be another week before it arrives. Till then I don't have my powerprobe, DMM, or any other tools to really delve into this project...

Any help would be greatly appreciated

 

Hey, the low speed fan going out can cause A/C issues, I'm experiencing this problem right now.

When the A/C system runs, the compressor compresses the freon, raising the pressure. The condenser is supposed to cool the freon, lowering the pressure. If the condenser doesn't have air flowing across it to cool the freon, it'll keep building up pressure. Once the high side hits about 600 PSI (it should be at about 180->250 from what I've read), there's a safety valve that vents the freon, so the system doesn't explode. Now there's no freon in your AC, and it doesn't work right. If you just put more freon it, it'll keep doing the same thing. The pressure might look like it is correct if you just look at the low side, but you've actually lost your ac charge.

Fix the low speed on your fan, then you should be able to recharge the AC.

 

BAD HUSBAND...

1. The ECM does not p/u faulty fan and AC operations. The high pressure switch is there to prevent the AC from being activated when refrigerant pressure is below spec. If the pressure switch is faulty, it can prevent the AC from being activated even with correct pressure.

2. No, I've not read/heard of situations where both low and high speeds are dead.... the low speed seems to be the problem due to the lousy design of the resistor.

3. Track down & fix the fan (fuse, relay, resistor, fan). Once done, evacuate and refill refrigerant. Make sure the Tech follows the refrigerant spec sticker front of the the radiator.

***You can keep driving the car w/o the fan by turning on the heat.

 

Thanks for the reply's guys... I really wanted to know more about this specific system. Your information was a lot of help

My fuses checked out good. When I get my tools down here I'll start by checking the operation of the fan assembly when power is applyed directly to it. If this is bad, I'll replace it and then move on to the a/c system.

I've got a set of a/c gauges and if the pressure is low, I'll be sure to re-charge to the specs on the sticker... I've got a couple cans of R134 hanging around in my tool box and have evac/recharged a/c systems quite a few times.

Although this was one of my first posts, I've read on here quite a few times... My wifes mini seems to be one of the cars that got most of the problems... My wifes mini has needed a new drivers window motor, door lock actuator, faulty stereo amp, and now the fan setup. The help is greatly appreciated

 

1. I thought AC evac/refill machines are quite expensive. I was thinking of buying a DIY unit to service the AC systems on my other cars... make sure there's enough oil in the system. What do you recommend?

2. In decades past when British cars were designed by Brits, the electrical systems were made by Lucas. When a Jag lost its headlights, instrumental panel light or ignition, one would say it's attacked by "Dark Man Lucas".

 

There are lots of other methods of recharching your a/c system without using a "machine." I own a set of a/c gauges and have a air powered vacuum tool. I own a nicer Matco version but the kind below should work just fine (you just need an air compressor) otherwise you can buy an electric vacuum pump but they are pricier.

http://www.harborfreight.com/air-vac...ors-96677.html

What I do is hook up my gauges to the high side and low side of the system. I then make sure my high side is closed on my gauge assembly and the low side is open. I hook up the hose (from my air compressor) and plug it into the vacuum tool and then the vacuum tool into my gauages (to the low side. I will usually let the system vacuum for about a half hour and then close the system (from the gauges). I disconnect the vacuum attachment and verify that the system has sufficient vacuum (by reading the gauges). I already have a couple cans of R134 that are 12oz. a piece. I then attach the can of refrigerant to my gauges and open up the low side through the gauges... you will feel the can suck down and can see the refrigerant pass through the sightglass in the gauges. When the can gets about half empty, you will need to start the car with the a/c on high to get the rest of the refrigerant out of the can... It will suck down the 12 oz can pretty quickly. The first can should be enough refrigerant to get the compressor to turn on... then the second can can be attached and by using the low pressure ****/valve on the gauges, you will slowly add a little more refrigerant. The method I've always used on my mustangs and families toyotas is to look at the sight glass and when I know I'm near the recommended capacity I look to see the bubbles dissapear (within the sightglass). Just be sure if you go this route and are on your second can, to take your time when adding refrigerant. Its always better to have a slightly underfilled system than overfilled. I then get my DMM and check the air temp through the vents.... from there, you're good to go!

 

My local autozone rents out a vacuum pump, it doesn't cost me a thing. I always tell them that my closest one doesn't have one, which is true. I had to call around a little to find one.

The quality of a real vacuum pump over the compressed air ones is amazing. The main reason you vac down the lines is to get water out, not air. At a near perfect vacuum, water boils at 60 degrees ferenheight. That gets any water out that might otherwise gum your system up. I always try to vac my manifold gauges out for 10 mins because of this if my gauges have been opened. Water in you ac will ice up and block the lines.

I'd fill by weight if possible, that's the only way to get it perfect. Do you have access to a scale that's accurate to the tenth of an ounce. Maybe a food or mail scale? You don't want to overfill. If you do, you can damage your compressor. I would Not suggest using the sightglass method, it doesn't have you charge it correctly. In high ambient heat, there will be more liquid in the system then on cooler days. If you fill on a cold day you'll undercharge your system.

 

What gauges do you guys recommend (to buy or rent) for evac & refill?

 

I just go to autozone and rent them. I don't have much choice on the brand.

I called around to all the autozones in my city, and on the 4th or 5th one, I found one with a vac pump and manifold gauge. Before leaving the store, ask them if you can test the manifold guages with the pump.

1. CRITICAL! Make sure the pump is filled with vac pump oil.
2. Plug in the pump, turn it on.
3. Not all the manifold gauges come assembled. make sure that one end of each hose is hooked to the manifold gauge. If the ends with the special ACME fittings are hooked to the side of the gauge, disconnect them.
4. Close both *****, make sure they are closed snugly.
5. Connect the yellow hose to the vac pump. There may be a cap you have to take off.
6. Listen to the sound the vac pump makes. You'll hear it sucking out lots of air, then you'll get to the sound of it pulling very little air, then it'll quiet down a little when it hits a hard vacuum. This should take 10-15 seconds. Make note of what that sounds like.
7. Open both *****. You'll hear the vac pump pulling more air out. It should take another 30 seconds, and you'll hear a hard vac again. Make sure the pump not sounding like it's still pulling lots of air out of the gauges. (sometimes the gauges are leaky)
8. Now attach the ACME fittings on the end of the blue and red hose to the holding spots on the manifold gauge. Once you get used to it, it should be a quick snap on/snap off, with almost no air leaking in. Make sure it hits a hard vacuum. Sometimes the fittings leak, or are hard to get to seal.
9. Jiggle the ACME fittings a bit, turn them, etc. You should keep the hard vacuum.
10. Leave the pump on, unscrew the yellow hose from the vac pump.
11. Turn the vac pump off. (always disconnect the yellow hose before turning the pump off.)
12. Look at the blue side of the gauge, note the vac pressure.
13. Wait 5 mins, look at the blue side of the gauge, the vac pressure should be exactly the same, if it's drifting, there's a leak.

If it passes all that, it should be ready for use.

First thing to do when you get home is to turn the vac pump on, open the *****, and connect the yellow hose and leave it running for 30 mins. It'll make sure the inside of those lines are nice and dry. You never know how the last guy treated the gauges.

 

Thanks for the tip!!!

 

A lot of what was said above it true but it should be noted that the quality of using an pump vs the air compressor method is not that different. When using the vacuum tool you ARE removing the moisture in the system.

I used to work for tony divino toyota in utah for over 6 years and only 2 years of that period did we use the a/c evac/recharge machine... After we found out that the tank had a leak problem we all started using the air compressor/vacuum suck down method and we never had a problem. It may not be a method everyone should use but is very reliable and for those who know how to do it correctly. Those that have never done it before risk overfilling. A mistake i've seen made is when a tech tries to introduce refrigerant into the system via the high side (compressor goes bye bye).

Both methods of evac/recharging the system are efficient.

 

This table shows show the quality of a vac affects the boiling point of water.
http://www.robinair.com/acsolutions/...um/chart12.gif

A good vac pump can get it down into the 29.8 range quickly.

I couldn't find the specs on the FCJ air powered vacuum, but this one
http://www.harborfreight.com/air-vac...ors-96677.html
only pulls down to 28.3" That will make water boil slowly, if it's in the upper 90. With a good vac, you're sure it'll boil in any weather.

 

"Dark Man Lucas" aka "The Prince of Darkness."

 

I was only using the harbor frieght version as an example... we all know they often make simple tools that can get the job done but ARE NOT known for great quality. I (and most the other techs I used to work with) used the matco air powered vacuum tool:

http://www.matcotools.com/Catalog/to...select=&page=2

As you can see, it pulls down to 29.7in/HG... Trust me, besides the countless customers cars I recharged with this tool (and never had a comeback using it), I also have used it on most of my vehicles and have never had an issue. I have a truck I drive out to Havasu 7 or 8 times a year (where it gets 125+ during the summer) and it always blows ICE COLD.

Kunnis, I know from experience your method works, but I know countless numbers of shops/techs around the country use this tool along with a set of a/c gauges with zero issues (if done correctly). Even when our a/c machine was working, most the techs had this air powered vacuum setup because when it got busy during the summer with a/c complaints, we didn't want to have to wait for the a/c machine.

Both methods can be used reliably to service an a/c system.

 

Yeah, that Matco one is much nicer then the cheap harbor freight one... I'd use it if I had it. And for the cost, the Matco one is cheaper then buying a vac pump. I've only seen the cheap versions of it.

 

It has held up over time and never let me down... the plastic cover on mine cracked and broke a couple years ago but doesn't affect its performance. The vacuum air pump is a cheaper option if you have an air compressor, but if you don't, then the vacuum pump is a great/cheaper way to go.

Its always good to give people options

 

Hey turbostang et al...

Did you fix your A/C yet?

My Radiator Fan 1 (low speed) and A/C stopped working. I disconnected the radiator wiring harness to feed power directly to test the fan. Both low and high speeds work fine. I also switched the Engine relay with the Fan 1 relay (same type) and the engine started up fine as well. All fuses/relays checked out good. So now I have a sneaky suspicion that if the A/C pressure sensor picks up low refrigerant pressure in the A/C system, it's wired to cut out Fan 1. But this sounds too stupid a design.

Anyway, I'm about to get my hands onto the A/C system. My question is: if refrigerant level is low, is it safe just to recharge it or should I do a complete Evacuation & Recharge? I'm concerned that some PAG oil may have escaped from the compressor. How does one know how much oil is residing in the compressor?

 

To test your low speed fan:

With your AC off...

Follow the direction on this link:

http://forums.bimmerforums.com/forum...d.php?t=736153

Bring up diagnostic 7.0 It shows your engine tempature in C. Run your engine at a high idle until it hits 105. The low speed fan should turn on within seconds of it hitting 105, and will stay on until your display hits 101. You may need to have a friend watch your fan to see if it kicks on, it'll drop down the temp pretty fast.

This will let you verify all the operation of your low speed fan. If the fan doesn't kick on by 109, there's something wrong with your fan. Turn your engine off and let it cool.



The ECU has no status on the fans, so the fact the fan isn't running won't do anything, but the fans only come on when they are told to, so it is compleatly normal for the fan to be off.

If the freon is low it will not turn on the fan... that is correct.

Yes, putting in a can of 134a is pretty safe the first time or two. After that, you have a leak bad enough that you need to figure out where it is and get it taken care of, and put some oil in to replace to replace the lost oil.

 

kunis -

I didn't know that the Test Mode can be run with the engine ON. Bentley only states to put the ignition key in Position 1.

So I take it that after you've entered Menu 7 (Temp and Speed) with key in Pos 1, you start the engine without exiting the Menu?

 

I got the Test Mode to work. Pretty cool to see the actual temp while driving. With ambient temp around 70-76*F, the coolant temp rarely goes beyond 91*C. This means the rad fan (and PS pump fan) only get used in the summer months and/or when the A/C is ON.

The Bentley Manual says Fan 1 kicks in at 105*C. I have to test that later this weekend.

 

Sorry I haven't been on here sooner, I've been really tied up with work. I found I had good power going to the fan connector/harness and so ordered the rock auto fan everyone on here recommended. Took 2 weeks to get here but quality was exactly as promised.... looked OEM. I took apart the front end this weekend and replaced the fans assembly. Had the whole job done in about an hour and was pretty straightforward.

Fans now work as they should. Haven't had a chance to fix the a/c yet but will try to get to it in the next couple days. I'll check back in with what I find.

Thanks guys for the solid advice. Now that my wife's car is almost done, time to get to rebuilding the front end on my 04 dodge diesel this weekend. If its not one thing, its another!

 

Checked the a/c relay tonight for power and grounds. Found that two terminals had power and two were grounded as long as the key was in the "on" position or the car was running. I was expecting to see some kind of change at the relay terminals when activating and de-activating the a/c from the controls in the car, but got none. Also tried jumping the terminals at the a/c clutch relay by going from a power to a ground.... Still no compressor clutch movement. Jumping the terminals should have turned on the compressor no matter what, shouldn't it?

A/C refrigerant was definitely low but when I topped some off into the low side I still couldn't get the compressor to kick on and the low side would only take a little refrigerant (car was running with a/c on high).

Wishing I had some kind of wiring diagram so I knew what terminals of the relay were supposed to have power and ground.

Anybody else with some suggestions?

 

If jumping the terminals on the compressor doesn't do anything, the clutch might be dead. The clutch doesn't come out separately; it must be replaced with the compressor.

The relays on my '06 #1 and #3, #2 and #4 are the same type/color. They can be alternated to test. I remember reading about the pressure sensor... when faulty it will not allow the A/C to be activated even when there's sufficient refrigerant pressure. You might want to check that out.

 

Thanks Cadenza, I will definitely check out the pressure sensor as well.

I may end up replacing the compressor but just want to be sure it's not something else (like the pressure sensor) that isn't allowing the a/c compressor to kick on.

 

Try BMW-PLANET. It definitely requires a certain type of browser configuration to work. Download Adobe's SVG viewer etc. Never could get it to work in Firefox, but all the schem's are there.