94 318 overheats in traffic (aux fan not working)

[dt29332]

Hello all.
My wife has a 94 318i that overheats when the AC is on and its in stop and go traffic. After some snooping around, I discovered that the aux fan does not turn on ever. I checked the 2 fuses associated with it and both were blown. After replaceing them, they just blow again. So, figuring it was a bad fan motor, I went to pull the fan off the car. That's when I noticed something strange. After removing the 4 bolts that hold the fan to the fan shroud, I could see the wiring harness. However, I could also see 2 wires that were obviously just tied in a knot around the frame. They wires were bare on the end. Are there more than one set of wires that go to the aux fan? I traced those wires and they go back to a factory harness that leads to the fuse box. they are obviously factory, but I don't know what they go to.
I also would like to know how to take the aux fan completely off. Please tell me you don't have to remove the bumper or the radiator...

thanks in advance

[Bear]

First,if she overheats in traffic then I would suspect the issue is with the viscous fan clutch (the one on front of water pump pulley). You have two fan relays (high and low ) in front power distribution box and a fan switch that screws into the radiator at the vuper right side. I would start with the fan switch at the radiator and take off the electrical connector and you should see three connection points. I beleive that the center is the hot point and the others are high and low speed. With igntion on, try shorting from hot lead on connector to one of the outer points on the switch and see if the fan runs, then the other outer point and see if the fan runs (you can take a volt meter and dermine which of the points on the connector is hot and go from there to the switch). The issue here is electrical one way or the other (relay/switch/aux fan resistor). Oh, I did not mention the resistor on the aux fan, that beast has been known to go bad as well. You could probably wire around it (temporarilly) to see if thefan works in that mode adn maybe isloate the resistor. I do not have a wiring diagram for a 318, I do have 5,6,7 series but that does not help you.

[Bear]

here is another place to go:
www.realoem.com
This will take you to a website for parts with diagrams, the webiste says under costruction, but click to enter, then click to access parts data base and it will take you to a screen where you can select your car and hunt for parts. The good thing is that it is like having a ETk/ETMfor parts since you can see the parts and perhaps see what you need to hook up.

[Bear]

Me again. Your 318 may have the aux fan switch/es located in the bottom of the radiator, engine side, and there may be two switches (one for high and one for low speed). If this is your case, then you would need to turn ignition on, and with volt meter see which of the electrical contacts on the electrical connector/s is hot and then short from the hot to one of the contacts on each switch and see if the fan runs (troubleshoots the fan switch). You do not have to remove bumper, but I believe you will have to remove radiator to remove fan, also loosen bolts on AC condensor and tilt it back (do not remove) to get the fan out. Start simple, hot wire from battery + to fan motor electical connector to see if fan runs, if she does, then we are at the point of checking fan switch/es. fan resistor, or fan relays.