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Discussion Starter · #1 ·
Been hearing a whining/groaning noise from the vents/dashboard as of late so upon further research thought itd be that the AC system was low on R134 and thus was causing the evaporator to make noises.

However upon going to get it regassed the mechanics noted that at 670g of R134 (The full amount) upon turning the AC, the High pressure (HP) line is seen to keep increasing pressure upwards of 300psi. He's stated that the problem lies within some sort of high pressure switch and that it'd be dangerous to use the AC due to the overpressure?

If it helps my last regas was 2.5 years ago (Did not own the car back then, only got it 4 months ago. Only know this cause of stamp under engine hood)
Also fyi, upon inspection he also noted that the electric fan is not turning on at all. What could be the cause of this, and would this have anything to do with my AC problems?

Thank you
 

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Which electric fan isn't running? Is the car a manual or an automatic? Who did the AC work before you bought the car? Did they add the correct amount of compressor oil? Has the AC worked properly since you bought it?
 

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Get your fan fixed.

300 psi is not too high for the system. It should climb and then shut off when over pressure.

Put some gages on and look at your pressures at rest and then when the system comes on. Report actual pressures.
 

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The electric fan is definitely the issue. They have a high failure rate. The fan motor is variable speed and the speed control circuitry is usually what failed.

Sent from my SAMSUNG-SM-G870A using Tapatalk
 

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Discussion Starter · #5 ·
Cars a manual so it only has one fan right? Dont know who did the AC work before i bought the car. They added the correct amount i assume, 25-30ml i think it was. And Well the AC has always 'worked' in a sense, though only blowing cold air at around 20 degrees celsius and the whining and groaning noise has always been there.
 

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Discussion Starter · #6 ·
The electric fan is definitely the issue. They have a high failure rate. The fan motor is variable speed and the speed control circuitry is usually what failed.

Sent from my SAMSUNG-SM-G870A using Tapatalk
How would i go about fixing it? Would i replace that module thats attached on top? Could it be a blown fuse? I just dont get how an electric fan can cause A/C issues.
 

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Discussion Starter · #7 ·
Get your fan fixed.

300 psi is not too high for the system. It should climb and then shut off when over pressure.

Put some gages on and look at your pressures at rest and then when the system comes on. Report actual pressures.
I think what my mechanic was saying was basically that it wasnt shutting off when over pressure. And i cant just put some gauges on, A/C work is illegal to perform here in AUS. without being licensed, hence proper equipment is only leased to mechanics.
 

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How would i go about fixing it? Would i replace that module thats attached on top? Could it be a blown fuse? I just dont get how an electric fan can cause A/C issues.
The electric fan problem is way more important than fixing the AC, as an overheat can ruin the engine. Working AC is useless with a blown engine.

Then take it to a proper AC repair shop for diagnosis.
 

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The electric fan not working is the cause of the a/c problem. It cools the condenser causing the hot gas coming out of the compressor to condense into liquid. Without the fan high side pressure will just keep climbing. Check for power and ground at the fan connector located at the right side of the radiator (two large wires) the 3rd small wire is the control signal from the dme. If you have power the fan assembly must be replaced. If your car has a manual transmission the fan is behind the radiator. Very easy to replace. If it's an automatic transmission the fan is in front of the condenser and the front bumper must be removed to replace it. It's easier than it sounds. I worked at a bmw dealer when our cars were new and replaced a lot of these fans. They had a lot of failures. New parts have an improved design. No need to go into the a/c system or take the car to a shop.

Sent from my SAMSUNG-SM-G870A using Tapatalk
 

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How would i go about fixing it? Would i replace that module thats attached on top? Could it be a blown fuse? I just dont get how an electric fan can cause A/C issues.
Spend some time to learn how an ac system works. Tons of information on it.

Need to learn it before you question it.
 

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The electric fan not working is the cause of the a/c problem. It cools the condenser causing the hot gas coming out of the compressor to condense into liquid. Without the fan high side pressure will just keep climbing. Check for power and ground at the fan connector located at the right side of the radiator (two large wires) the 3rd small wire is the control signal from the dme. If you have power the fan assembly must be replaced. If your car has a manual transmission the fan is behind the radiator. Very easy to replace. If it's an automatic transmission the fan is in front of the condenser and the front bumper must be removed to replace it. It's easier than it sounds. I worked at a bmw dealer when our cars were new and replaced a lot of these fans. They had a lot of failures. New parts have an improved design. No need to go into the a/c system or take the car to a shop.

Sent from my SAMSUNG-SM-G870A using Tapatalk

What randy said. Fix the fan and then see what you have.
 
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