Jeff Bergman

Hello Everyone. I'm new here.

The dealer told me that my cooing fan died and needed to be replaced. Being pretty handy, I picked up a new BMW fan, thermostat and lower radiator hose sensor. Just got done with the job and the new fan doesn't come on.

Now I'm not sure what the problem is.

Any thoughts?? Also, does anyone know of a way to test the fan? It has a two large wires and one small. I thought one would be a ground, but it doesn't seem to be. I'm looking for a manual way to test the fan, but don't want to connect it wrong and burn it up.

Any suggestions?? Very frustrated!!!

twh

Go to:
WDS BMW Wiring Diagram System - 5 E60 E61

Use Firefox. Make sure Java is enabled and click to allow Java to run. Once in the app click "Drive" then "Engine Management....N62".

You need to be careful. I'm not sure you can just bench test the fan. The fan is not a simple DC on and off. It is controlled by a PWM signal (pulse width modulated) that allows a duty cycle to let the fan be, essentially, variable speed.

Jeff Bergman

twh. Thanks for the response. I was able to go to the site but wasn't really sure what I'm looking at. Sadly I went through the work of replacing my fan with a brand new fan and shroud. The new one doesn't seem to be turning on. I let the engine run for about 5 minutes. No joy.

Do you know of a way to manually activate the fan or should I let the car run for a longer time? I also turned on the AC. Still no luck.

Do you know if there is any programming required for a fan replacement? Mine is an 08 550i.

Thanks.

seanjordan20

When you changed the parts did you also do a fluid change. Did you do the bleeding procedure since you changed the thermostat? After doing the bleeding procedure two or three times I would run the car for 10 mins with the heat blowing high. You should then see the fan cut on and off.

Jeff Bergman

Hey Seanjordan20. Thanks for chiming in. Yes I did a fluid change and topped off the oil as well since some of that leaks out.

Ok so here's the deal. From what I can tell, there must be a different bleed procedure for my 08 550i. It doesn't appear to be an electronic water pump. It's driven by a pulley and the only electrical connection seems to be a sensor, not an electric motor. I could be wrong.

When I started the car, I ran it for about 5 minutes and turned on the AC which "I think" should have activated the fan right away. I'm hesitant to keep running the engine not knowing if the fan will come on.

Thoughts?

Thanks.

Jeff Bergman

Oh, also, I did try the bleed procedure about holding down the accelerator for 10-15 seconds and nothing happened.