You see that sensor on the AC receiver/drier? It looks disconnected, I'm guessing it's for it! It's either the refrigerant pressure sensor or the refrigerant temperature sensor (one of them has 3 prongs, the other has 2, I always forget which is which).
The A/C Receiver has 1 cable connected to it, and this one looks like it doesn't go anywhere. On the side where it looks like it is (on some models) mine has a bolt. Looks like on the picture
It looks like you have the wrong receiver/drier. It's supposed to have 5 holes, with one blocked off by a bolt. Yours has 4 with one being blocked off by a bolt. I'm guessing your car was serviced once upon a time, the wrong receiver drier was bought, and instead of installing the correct one the wrong was used and the refrigerant temperature sensor wasn't ever installed. I confirmed that it is indeed the wire for the refrigerant temperature sensor. It's not a particularly useful sensor, I suppose you could do away without one. My recommendation is: if one day you need to service your air conditioning, then replace the receiver drier with both new sensors, and just plug both of them in (you need to replace the receiver drier anytime the system is opened to the atmosphere anyway), but until then, don't lose any sleep over it.
Wow thanks for this reply! It could be this ac receiver that's wrong and it's causing my engine fan to work at 100% all the time?
When I bought a car over a year ago the fan control module was blown, so I got a replacement (it is a correct one for my vin number), but it still spins at full speed.
I keep it unplugged as the weather isn't too hot for now and try to keep out of congestions so car doesn't overheat. A/C works normal though which is interesting.
I got no codes wrong on tester. Tester told me that MAF sensor was bad and one can bus was bad, so I got fixed all this.
But could it be this a/c receiver that's causing a fan to spin at high speed?
As far as I'm concerned, the refrigerant temp sensor has nothing to do with fan operation, it doesn't even really have much to do with HVAC operation either. The variable-displacement compressor is controlled by low-side pressure, and even if it were controlled electronically rather than mechanically, it would be controlled by actual cabin temperature vs desired cabin temperature. It's not a critical sensor.However, to help you further, I will need you to update your profile and put the model of your car as well as its model year. I need that information to help you further! (There were some differences between model years on how the cooling system operates).
I updated some informations in my profile, but will write it here as well. My car is W202, 1998, Classic, C180, manual with m111.921, VIN number is: WDB2020181A619457. Hope it helps, and thanks
Well normally I wouldn't think that sensor would cause your fans to run at full. But since you already changed your fan controller, it might not be such a bad idea to try buying a refrigerant temperature sensor and plugging it in. Then you could try blowing some cool air over the sensor, and seeing if it solves the fan issue (and if it does, we can find you the right receiver drier and you can install everything properly).
I heard It is highly possible that the AC module is faulty and that could cause the fan works at high revs. My ac only works at full hot or full cold so i assume this could be it.
Could you please tell me where the module is? So I can get a part number and order a replacement?
Thank you very much
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