95 M3 Mishimoto fan

[dougpiston]

My tech just finished doing the head gasket on the car and it seems the previous owner installed electric fan. Issue is it seems to connect via the AUX fan. That doesn't seem correct to me. Shouldn't be connected the temp sensor sticking out the passenger side of the radiator?

Thanks

[boarder2k7]

It should preferably be connected to a fan controller with its own power source. At minimum it needs a relay that is switched by the stock system, again with its own dedicated power feed.

[TH3 Shifty]

Bimmerworld make a complete wiring solution for the electric fan complete with relay. About $170 but it's complete and very easy to install

[Moron95M3]

Or just go back to a mechanical fan.

...which will 100% work, and not cause another head gasket job...lol

[huhmanbeing]

I've got the mishimoto fan and like it quite a lot, however since I don't do wiring I let a shop take care of that part for me. Complicated mechanical work? No problem. Wiring diagrams? My head hurts. That being said, you're absolutely correct that the fan should not be wired into the aux fan. A properly wired fan will be as boarder described it.

[dougpiston]

Or just go back to a mechanical fan.

...which will 100% work, and not cause another head gasket job...lol

Believe me, that was my first choice. I work for a dealer and the techs talked me into keeping this one. I've own the car a little less than a month and it hasn't overheated in the 100 miles I put on it before discovering it needed the head gasket.