If there is no power in the harness to the fan i would guess that there is a break in the wiring based on the other testing you ve done.
Bmw e36 auxiliary fan not working.
You should be careful as the current draw is substantial.
You might look into.
Auxiliary fan not coming on.
If the fan is not operating check the power connector at the base of the fan and make sure it s seated.
If the fan does not run check for 12 volts at terminal 30 in the relay socket.
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If this still fails to turn on the fan i suggest you turn off the engine for now and consider troubleshooting other aspects of the cooling fan electrical system including the low speed fan relay.
If so retry the test jumpering from terminal 30 to 87a.
Replace the high speed relay.
If the fan itself is the issue the part can be costly but the replacement is relatively straightforward so long as you re careful not to damage the delicate radiator fans.
Go to my website and bmw forum.
Could be the fan could be the sensor.
I just tried my a c for the first time today and my auxiliary fan is not working so i guess i ll be checking mine out next week i know soon as i turned the a c on the 318 the fan would start right up.
If it does the fan motor is ok.
If the fan does not run on high speed check to see if your application is using a 5 pin relay.
You could also apply 12v to the fan itself to make sure it works.
The fan should come on at high speed.
Bmw e36 m3 evolution.
If the fan is not working yes if you idle for a long time it will get hotter.
Trace the harness and fix it or bypass it.