Electric Fan Not Working

[mperkins40]

I am having an issue with my X5 35d that I have been troubleshooting and I am at wits end. I would be really grateful if you could shed some technical assistance.

While sitting in a parking lot with the engine idling during chilly and humid/rainy weather, I noticed that the air in the vehicle suddenly also got humid (AC stopped working despite ac light still on). I confirmed that the compressor clutch was not engaging. I figured it was low on refrigerant and would just need to be topped off and I would be good to go. Local shop through gauges on it and advised that the pressure was good. I checked all the corresponding AC circuit fuses and they are all good. I can engage the compressor clutch with DISV57 software. However, I have also noticed that the electric (coolant) fan is not coming on at all either which used to come on at a minimum during engine startup and whenever the AC was turned on. I am now suspecting from wiring diagrams that because the fan is not running, it is preventing the compressor from engaging. I can power the electric fan using DISV57 software. The electric fan cutout relay is open as I have power going between both hot leads. The fan has 14.7v after fan's electrical connector. I have continuity between the black/Green wire from the electric fan to the DME controller; continuity is 0.4-0.5 ohms which I am not sure whether that is too high for such a small diameter wire over about 5-6 feet length.

I am out of ideas and at this point I do not want to bring it to the dealership as they will just start replacing/throwing parts at it at my expense.

Also, although, I suspect the electric fan not coming on as being the culprit, a question I do have, is it possible that the refrigerant is too high - is there a sweet spot for the AC pressure sensor? I noticed on the BMW that there is only one sensor while most other makes have a separate high and low pressure sensor/switch.

[ard]

"Gauges" are not an adequate way to evaluate system fill.

You ask if it is possible the 'refridgerant is too high'...how could this possibly happen??!?!?!?

Did you add a can?

The only way to properly fill is: pump down/evacuate, then fill by weight. As I recall the tolerance is +/- 0.02lbs

Although I am not sure your issue IS the fill....

Do you have software to interrogate the IHKA for errors, codes?

[mperkins40]

Yes DIS initially had DTC A72F (Magnetic Clutch AC Compressor). After I went through test schedule, and activated the magnetic clutch the system through the DIS software, software said error no longer present.

Fan still not working.

[Toothbrush]

Out of curiosity, do you know what your coolant temp is showing?

[mperkins40]

I have not looked at that parameter aS of yet because the fan wasn't coming on at all. Probably will get to later today as the coolant tempt sensor is on my to do list. ...

[ard]

Originally Posted by mperkins40

Yes DIS initially had DTC A72F (Magnetic Clutch AC Compressor). After I went through test schedule, and activated the magnetic clutch the system through the DIS software, software said error no longer present.

Fan still not working.

Odd for the system not to work and fan not turn on, yet no codes...

Did you add freon.

What year, or better what last 7 vin- I can look it up.

[mperkins40]

2010 LJ99404

[ard]

Originally Posted by mperkins40

. However, I have also noticed that the electric (coolant) fan is not coming on at all either which used to come on at a minimum during engine startup and whenever the AC was turned on. I am now suspecting from wiring diagrams that because the fan is not running, it is preventing the compressor from engaging. I can power the electric fan using DISV57 software. The electric fan cutout relay is open as I have power going between both hot leads. The fan has 14.7v after fan's electrical connector. I have continuity between the black/Green wire from the electric fan to the DME controller; continuity is 0.4-0.5 ohms which I am not sure whether that is too high for such a small diameter wire over about 5-6 feet length.

The VIN helps.

Is this your wiring schematic?

https://www.newtis.info/tisv2/a/en/e...ooling/hAa9TPF

The eletric fan is, as I recall, controlled by a signal from the DME. So that Blk/Grn wire is a fan speed control:

Just looked it up on newtis:
https://www.newtis.info/tisv2/a/en/e...ooling/XnZEwDx

The DDE control unit activates the electric fan by means of a square wave signal with a duty cycle of between 5 % and 95 %, thus activating various speeds at the electric fan. The electric fan features its own positive and ground supply.

So:

Fan isnt working
DME is bad
DME is not telling the fan to come on due to erroneous inputs
DME is properly telling fan not to come on.

And do keep in mind that this might be unrelated to the AC issue.

I havent found anything else that helps... check the coolant temp sensor. How are your operating temps???

[mperkins40]

Thank you ard. Your diagram is much nicer as I was using one from the Mitchell manual that requires me to filter out the gasoline versions. I was just messing around with DIS again, and I am pretty sure I have a compressor issue. I think the compressor control valve is not calling for the clutch to engage. I also think you're right in that the DME is involved. I will replace the compressor and take it from there.

Operating temps - haven't been out driving vehicle since this issue arose. I am about to troubleshoot the coolant sensor though.

[ard]

newtis.info is invaluable.....

Keep us posted