Hi guys. This is my first post here. I've scoured the interwebs trying to find a solution to my problem but have had no luck. The a/c compressor clutch doesn't engage. It does engage if I jump it but cold air still does not come out of the vents. The only clue I can think of is that the radiator fan doesn't turn on either. Could that be part of the problem? I've read somewhere that the fan has to be on for the a/c to work.
Check fuses 28, 62 and 63. Those are the ac fuses. Use a digital volt meter to properly check them. Place a meter lead into the openings on the top of each fuse. Any voltage reading other than 0 volts DC means fuse is bad. If a new fuse blows you have an electrical issue.
If it’s not a fuse, take your car to a professional automotive air conditioning shop. Likely the refrigerant (R134a) is gone. Do not apply power to the electric clutch as this might damage the compressor. Do not attempt to fix the problem by dumping R134a into the system. Modern ac systems require a precise amounts of refrigerant and compressor oil. Over-or under-filling the system will cause problems.
The shop needs to:
- evacuate any remaining refrigerant
- vacuum test the system (usually for 30 minutes)
- add the precise amount of refrigerant
- add fresh compressor oil.
Now, if the ac went out all of a sudden you need to have the shop add an ultra violet dye to the refrigerant. That way when the ac stops again the shop can use a uv light to find the leak.
The E46 ac system is pretty robust. I’ve heard/read about very few issues with this system.
Now, the issue could be related to the automatic climate control module (IHKA in BMWspeak) that sits in the dash. If the ac shop says the refrigerant level is ok then the next step is to scan the car with BMW-specific software. Find a reputable indie shop that specializes in bimmers at www.bimrs.org.
So I take the fuse out and put the multimeter where the fuse was?
No, you read that wrong. Typically on top of most blade fuses, there will be a test spot at the top looking like a "-" dash. That is where you would place the leads at, one on each end.
Darin
Current:
16 220i Active Tourer Platinsilver MET (C08)/Dakota Black (PDSW), P7ACA, P7LDA, P7LHA, P9BDA, 6sp Manual - Wife's new toy!
05 325it Electric Red(438)/Gray(N6TT) ZCW, ZSP 5sp Manual Back set cover, trunk mat, Euro Infra-Rot front windshield, and mud flaps! Mr. Wagon My new Winter car.
05 M3 Imolarot II(405)/Gray(N5TT) ZCW, ZPP 6sp Manual C.F. Lip, CSL diffuser, SSK, Euro Infra-Rot front windshield and a trunk liner! Mr. Go_Fast Stored for the Winter
Past:
95 318is Montreal Blue Met (297)/Beige(K1SN) RIP, killed by an Idiot.
84 M535i gray market Burgandy Rot Met/Black Leather Lowered by Intrax on bilies, poly everywhere, B&B cat back system, K&N, and a hitch! Da Beast - Still running w/400k+!
91 316i euro Tizianrot/Gray cloth - E-36 w/M-40 RIP, but great on gas! Best was 38 MPG
82 528i euro Saphire Blue Met/Blue Leather RIP
79 525 euro Green/Green RIP
79 318 Silver/Black - The first one that got it all started
M-Flight Member
There are low and high limit switches that will prevent the compressor from running if pressure (charge) is too low or too high. Given that you are able to run the compressor and there is no cooling chances are good you have low refrigerant charge.
I'd be checking pressures before chasing any electrical red herrings.
Last edited by ross1; 04-21-2019 at 03:57 PM.
If you can leave two black stripes from the exit of one corner to the braking zone of the next, you have enough horsepower. - Mark Donohue
Right. Have it properly evacuated, and recharged before doing anything else.
E46 evaporator leaks are super common.
ASE and BMW Master Certified Technician
Exactly
Seems that BMW has a problem with evaps and expansion valves. I went through 2 evaps and 2 expansion valves in 15 years of ownership with my 1985 325e. However, the ac in my 2001 330Ci still works fine according to the guy I sold it to.
The evaporators get clogged with junk, and that starts to eat the aluminum, thus a leak. I had to replace the original in the E-36 when I first got it to get the A/C working again. I think removing the bumper to clean it every couple of years can help, but I don't think the average person would do this.
Darin
Current:
16 220i Active Tourer Platinsilver MET (C08)/Dakota Black (PDSW), P7ACA, P7LDA, P7LHA, P9BDA, 6sp Manual - Wife's new toy!
05 325it Electric Red(438)/Gray(N6TT) ZCW, ZSP 5sp Manual Back set cover, trunk mat, Euro Infra-Rot front windshield, and mud flaps! Mr. Wagon My new Winter car.
05 M3 Imolarot II(405)/Gray(N5TT) ZCW, ZPP 6sp Manual C.F. Lip, CSL diffuser, SSK, Euro Infra-Rot front windshield and a trunk liner! Mr. Go_Fast Stored for the Winter
Past:
95 318is Montreal Blue Met (297)/Beige(K1SN) RIP, killed by an Idiot.
84 M535i gray market Burgandy Rot Met/Black Leather Lowered by Intrax on bilies, poly everywhere, B&B cat back system, K&N, and a hitch! Da Beast - Still running w/400k+!
91 316i euro Tizianrot/Gray cloth - E-36 w/M-40 RIP, but great on gas! Best was 38 MPG
82 528i euro Saphire Blue Met/Blue Leather RIP
79 525 euro Green/Green RIP
79 318 Silver/Black - The first one that got it all started
M-Flight Member
Bookmarks