AC issues

[Usmcorpse]

2012 BMW X5 35i

AC blows cold one day and next day blows hot. It's a 50/50 lottery every time the vehicle is started if the AC will blow cold. Ideas?

[RL18]

Originally Posted by Usmcorpse

2012 BMW X5 35i

AC blows cold one day and next day blows hot. It's a 50/50 lottery every time the vehicle is started if the AC will blow cold. Ideas?

If it blows cold one day and warm the next then that tell me that you have a compressor issue and most likely a compressor electrical issue.

You can check the amperage of the compressor to make sure it's not pulling high amps then kicking off on a limit. Of course you need to know it's normal amperage which I don't know lol. Or you could have a loose connection somewhere. Compressors are usually very reliable, so I would be leaning more towards electrical especially if the problem is intermittent.

[DJ///M5]

Recently dealt with this scenario for my 2011 x5 (3.5) N55 Motor. The AC was intermittent. On startup it was cold then transitioned to warm.

Also experienced intermittent electrical gremlins for glove box, wiper fluid, rear hatch operation.

I had Firestone Auto Care check Freon level which check out Ok with no leaks

Next I used my Schwaben Scanner to check modules. The scanner captured (2) AC related Fault Codes for: JBE Compressor Clutch and JBE Control Valve in AC compressor. Junction Box Electronics (JBE) is a controller gateway module for numerous operations. Check bmwtis.com for more details.

Deploy a scanner and/or ISTA/D software to gather additional info. I maintain four M's and standard X5 (3.5). Start with simple check points first. I recall having faulty AC issues that ended up being a $5 schrader valve.

In my case:

Solution: My diagnosis led me to purchase a JBE Module ($400). Independent shop tried programming the JBE, but was unable to complete the task. I ended up at a BMW Dealer for module programming. While at BMW Dealer I was informed that the Footwell module (FRM) required replacement under Service Information Bulletin 01 20 16 (Free repair for 10yr/156,000 miles)

[Usmcorpse]

Originally Posted by RL18

If it blows cold one day and warm the next then that tell me that you have a compressor issue and most likely a compressor electrical issue.

You can check the amperage of the compressor to make sure it's not pulling high amps then kicking off on a limit. Of course you need to know it's normal amperage which I don't know lol. Or you could have a loose connection somewhere. Compressors are usually very reliable, so I would be leaning more towards electrical especially if the problem is intermittent.

Where should I look for the amperage data?

[RL18]

Originally Posted by Usmcorpse

Where should I look for the amperage data?

Well I've been looking through bmw newtis and this page is about all I can find.

https://www.newtis.info/tisv2/a/en/e...-conditioning/

I would be willing to bet it's either something to do with the pulley not engaging the compressor or the compressor is dealing with an electrical issue. Just about all that'll happen to a compressor if it's bad is it'll cease

It seems like most fixes for that type of issue is a new pulley. Do you have any codes from this? If the pulley wasn't engaging it should throw a code

Edit: I forget that car compressors are run of the clutched pulley! Not 220v like what I'm use to. I would look towards measuring voltage and amperage from the pulley at the connector. Should be 12v and about 5 amps if it's engaged