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Discussion Starter · #1 ·
Hello all:
I recently purchased a 1993 Euro M5 and seemingly have some problems with the air con system. Firstly it doesn't blow cold. The fan speeds all work but should I hear/feel the compresssor engage? Also where is the location of the R134 sight gauge? Lastly should I need to replace components any suggestions on compatability?

Thanx for all advice rendered!
 

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Could be a blown fuse.
Could be a faulty blower fan resistor
Check wiring to trinary switch & compressor.
Check these & the wiring to them that are usually very brittle.
Even if they look ok, quite often the copper core is dust !

My guess.
From past experience the aircon has discharged by sounds of things.
Likely an "O" ring seal or fractured condenser.
Air con equipped vehicles are equipped with a trinary switch.
A hi -low pressure switch.
Too little pressure = nil engagement of compressor
Too much pressure = nil engagement of compressor
In both cases, the system is outside safe operation for vehicle or a/c system.

I would check the basics.
Then, get an a/c specialist to vac the system to draw as much condensation out of the lines,
then introduce a UV dye.
That will point to the main leak paths.
If the a/c has been out of commision a long time, I would change the reciever
drier regardless.
This is a moisture catch can.
It's contents can eventually break up.
If this happens, dealing with the debris is a painfull expensive experience.
 

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Darren,

Can a Air Con specialist do any tests on the system first? Or is it the case of getting the system done and then looking for the leaks?

Thanks

Tom
 

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Discussion Starter · #4 ·
Thanx Tom for your input. Actually this week I'm going to embark upon the systemic procedure as outlined by Darjec Racing in their prior post to me. I still unsure of parts availability if needed. Will Air Con system components off a U.S E34 M5 be applicable?

Thanx-D.Gregz
 

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Darren,

Can a Air Con specialist do any tests on the system first? Or is it the case of getting the system done and then looking for the leaks?

Thanks

Tom
Tom,

If you find a decent A/C specialist, his equipment will first evacuate the a/c system of old refrigerant and then vacum test the system.
This vacum test will show up leaks.

An alternate step is to pump some dye into the system which will show up in any area that is leaking & letting gas escape.

Regards,

Alan.
 

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Alan

Thanks for your info, its just I was abit unsure of handing over cash to a company who could do regasing of the system, but they said that they could not do any tests and would have to spend the 70 quid to get it done before they could see if it was holding/working correctly.

Thanks

Tom
 

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Not strickly true...

They perform the leakdown test BEFORE they put fresh R134a in....

I wouldn't expect them to charge you full whack if you had a leak,
but certainly charge for 30mins work...

If your A/C is dead (no light illuminates) then barring electrical gremlins
suspect a leak...and treat accordingly.

Regards,

Alan.
 

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I know suggesting Halfords is generally a bad thing to do, however on this occasion I think they are the way to go.

Halfords will regas you A/C, and if your system will not hold a charge they will not charge you anything. I used them about 18 months back on my 94 6sp on this basis.
 

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Some leak paths on a/c system are very slow to discharge.
the compression seals on the hp/ lp tubes to the Condenser.
The same applies to the receiver drier can.

You can charge the system & it will hold pressure.
A month later = pressure below X psi = no operation.

These leaks draw more mositure into the circuit & make it much harder to
keep the system clean.
Moisture not drawn from the system kills efficiency.

Vaccing the system & adding the dye is best practice prior to gassing.
Our systems get efficiency through mass = 1650gms of oil & gas.
Thats one big charge compared with todays vehicles running @ 500-750gms.
 

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If your A/C is dead (no light illuminates) then barring electrical gremlins
suspect a leak...and treat accordingly.

Regards,

Alan.
Alan,

The light comes on but nothing happens. So not sure if it is the pump?

Thanks
 

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Right, my aircon is always on, and I had it last serviced/recharged last May.

It's been gradually getting less and less efficient over the last couple of months, so thought it was time for a recharge.

I took it to a very nice gentleman (this is Liverpool remember) that only charged my half-price as the system wouldn't cool any more which he explained was due to a knackered compressor or clutch. When you switch the aircon on you can hear a small click with a corresponding 200rpm or so rise in revs and the light comes on but the air doesn't get any cooler.

I assume BMW will want to bum-rape me for this part, but looking at RealOEM and BMW Fans ETK it seems there is a Bosch & Seiko part for this car and it doesn't state which one I have when I put my VIN in.

It also seems that this part number is used on everything from 318s to 750s and everything in between, but I'm sure that can't be right as BMW never makes anything that easy - do they?

So what are my choices? Will a 2nd hand one from almost any car be fine assuming I get it cheap enough, or do I have to find out what mine is exactly to be sure of a match?

TIA Tony
 

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Tony, I might have some aircon parts for sale in about a month if you can hang on - I've bought Alpine Amy's complete system .... now, mine is broken, but I don't know which part, so you'd be welcome to any of the bits that are left (obviously once I know if they work)!
Stephen
 

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You're probably going to have to get dirty & have a look at the
compressor to verify which make you have.

My 3.8 has a seiko unit.
 

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The compressor from Alpine Amy was a Behr unit .......I will be taking the compressor off Sebring Sienna this weekend in our weight reduction campaign and will ask my a/c friend , Mark , to test it Tony .....as I am having a new condensor fitted to my 850CI on Saturday .

By the time we get all of our a/c woes rectified it will be winter !
 

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I've got someone looking at mine next week to see if it's easily repairable.

I'll let you guys know once I know.
 

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Best of luck Tony ......the last thing you need is to sweating your way through summer !

D
 

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Best of luck Tony ......the last thing you need is to sweating your way through summer !

D
I sweat in winter so me, summer, leather seats and no aircon is not a good combo, although it's me that ends up looking worse.
 

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Hi can anyone recommend a place i can sort mine out as the a/c on my car either 1. needs a recharge or 2. is faulty, 3. Ashamed to say may be i am not turning it on properly, pls note the green light comes on but the revs don't change to indicate anything. any advice is welcome. Thanks, Y.
 

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Just to let you know that mine is all ok now. I had the car tested to see if there was any gas in there. Yes there was. Just not enough to kick in the A/C, which is lucky as I didn't have a chance to test that the compressor works with a live wire.

Had the system pressure tested and then regased. 1.5kg of gas.. More than a Ford Galaxy. Runs really nice now.. Just aswell I had some gas in there other wise I could of be looking at a ££ to get the bits.

Just had to get a new R12 to R134a adaptor lowside. Which was cheap as. best bit is it cost me 2 pints in total.
 
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