Ac not working, Checked Refrigerant, What else to do?

[upallnight]

Originally Posted by TECN1K

I'm surprised nobody has killed themselves from DIY freon kits.

In the old days with R12 refrigerant, you could have killed yourself with hooking the low side hose to the high side of the system, since a can of refrigerant was never designed to hold a pressure exceeding 300 psi. But with R134 it is pretty idiot proof since the connectors are not the same size and a low side connector can not fit a high side connector, but there is always that one idiot that will MacGuyver something together and end up killing or hurting himself or other people.

Best advice is if you don't know refrigeration system take it in.

[bcredliner]

with having a well recommended BMW focused shop diagnose the problem. I do almost all of my own work but I leave other than the basic troubleshooting to see if it is something simple to an experienced air conditioning tech.

You can check the aux fan. If the fan has failed or isn't getting power the air conditioning won't work. When the air conditioning is on the aux fan should be running.

You can check the air-conditioning related fuses.

If this is your first BMW you may not be aware that the dial on the dash that in one direction shows a red dot and the other a blue one needs to be turned to blue and the snowflake button activates the air conditioning.

You can check if the compressor has power. The clutch on the front of the compressor should turn when the air conditioning is on.

Pressurizing the system beyond the recommended pressure for any reason is dangerous. Recharging the system without reading both the high and low pressure sides is too easy to overfill the system, causing damage-can seize the compressor. And the process of evacuating and refilling the system includes a vacuum and adding both refrigerant oil and refrigerant.

[shevin]

Respond 1: the can I bough has pressure measurement it was 44 PSI.
Respond 2: I didnt put it in the air, I barrowed a vaccum to suck the reffregirant and recycled it.

Update1: The fan infront of the radiator doesn't spin when I turn on the AC. how can I fix that ?

[bcredliner]

Next step--check to see if there is power getting to the fan when the air conditioning is on. That will tell you if it is the fan.

[upallnight]

Originally Posted by shevin

Respond 1: the can I bough has pressure measurement it was 44 PSI.
Respond 2: I didnt put it in the air, I barrowed a vaccum to suck the reffregirant and recycled it.

Update1: The fan infront of the radiator doesn't spin when I turn on the AC. how can I fix that ?

1. A static pressure of 44 psi will mean that the refrigerant charge is low, I assume that the compressor wasn't running. The low static pressure may be low enough for the low pressure switch to kick in preventing power to the compressor.

2. A standard vacuum pump does not recycle the refrigerant from an AC system, you need a recovery pump with a recovery tank to recycle the refrigerant.

To verify that it is a fan fault, you will need to get the X scan as suggested at the beginning. The fan fault will be located in the DME module, or you can buy a new fan and install it and hope that it will correct the problem.

The bumper cover will have to be removed in order to remove the old fan and install the new fan. Fan prices range from a couple of hundred dollars to 600 dollars for an BMW OE fan. I would stay away from the cheapest fan as they are cheap for a reason, no quality control so the fitment is probably off and no guarantee.

It's about a 3 to 6 hour job depending on your skill, and the type of tools you have (regular hand tools or power).

It's about a 800 to 1200 dollars job if you brought it in depending if it's a dealer or an Indy.

[upallnight]

Originally Posted by bcredliner

Next step--check to see if there is power getting to the fan when the air conditioning is on. That will tell you if it is the fan.

There is a constant 12 volt feed to the fan no matter if the ac is on or not. The aux fan is also used for cooling the coolant in the radiator. If there is no constant 12 volt at the fan connector that means the 50 amps fuse has blown and the only way that fuse is going to blow is if there a direct short in the fan.

[bcredliner]

Originally Posted by upallnight

There is a constant 12 volt feed to the fan no matter if the ac is on or not. The aux fan is also used for cooling the coolant in the radiator. If there is no constant 12 volt at the fan connector that means the 50 amps fuse has blown and the only way that fuse is going to blow is if there a direct short in the fan.

Yes there is constant power to the connector and the aux fan is also used for supplemental radiator cooling. However, there is an AC aux fan switch and also a radiator fan switch that closes the circuit. Power to the fan was intended to mean to check if there is a complete circuit on wires that go into the fan to see if the fan is the problem or the AC switch. You could also do the test at the connector which would also verify if the fan or switch is bad. I was thinking it would be easier check near the motor as it could be that the problem is only the low speed that runs for AC.

[TiAgX5]

Those not familiar with automotive AC systems need to find a good shop to do the work.

Those who choose to DIY should look into the Inficon Vortex (and a good scale). These can be found online/used for a few 100 dollars (pays for itself with first DIY).

[esntrk1]

I would start trouble shooting at the compressor. Start the car and set the AC on max. Then visually inspect the compressor. The pulley should be turning with the belt. That means the clutch is engaged. If the pulley is not turning, you need to check to see if there is 12V applied to the compressor it at the connector. Use a voltmeter to check that. If you have 12V there, then it's your clutch. If you don't have 12V then you can start trouble shooting your fan. I'm making the assumption here that the DME is working properly. It's really the gate keeper. If the fan is good, it will enable 12V to the compressor. The opposite is also true. And, the fan doesn't have to be running when the AC is running. However the fan should spin up when you start the vehicle as part of diagnostics. That's all I have gathered from troubleshooting my AC over the past few months. See my other post today for a list of AC unit suppliers.

[shevin]

Originally Posted by bcredliner

Yes there is constant power to the connector and the aux fan is also used for supplemental radiator cooling. However, there is an AC aux fan switch and also a radiator fan switch that closes the circuit. Power to the fan was intended to mean to check if there is a complete circuit on wires that go into the fan to see if the fan is the problem or the AC switch. You could also do the test at the connector which would also verify if the fan or switch is bad. I was thinking it would be easier check near the motor as it could be that the problem is only the low speed that runs for AC.

I checked there is a 13.4v DC voltage on the aux fan using my mulitmeter