Engine fan not turning off

jooksingjai · 08-13-2011, 01:32 AM

Hello,

I came back from a movie at the theatres and my car wouldn't start......the battery was dead. As I jump-started the car, I noticed/heard what sounded like a fan near the engine. This fan was on the whole time even though the car was turned off and the key wasn't even in the ignition.

Does anyone know what is wrong? I own a 2000 BMW 328Ci.

Much appreciated, thanks!

Ceeker · 08-13-2011, 07:14 AM

Well, first off your fan drained the battery. 2nd it's your aux fan staying on which could pose a fire hazard since your wiring is going to get awfully hot. it might be the thermoswitch sending a false signal to the fan making it stay on.

BmW1819 · 08-13-2011, 09:45 AM

in other words u need a AUX fan

dissconnect when u turn off the car and when u drive it plug it back in

Ceeker · 08-13-2011, 12:05 PM

Quote:

Originally Posted by BmW1819

in other words u need a AUX fan

dissconnect when u turn off the car and when u drive it plug it back in

the aux fan is working so it shouldn't be that, no? there has to be a switch to activate the fan when the motor gets above normal opp temperature. it should also cycle off when the temp drops. if it is staying on there is interruption to cut power to the fan. So, if by chance the thermoswitch is faulty it will make the fan think the motor is above normal temp and stay on. But it could be other things but I don't know how the circuitry is designed for the newer models

jooksingjai · 08-13-2011, 02:47 PM

Yea I turned unplugged the aux fan and it turned off so it doesn't drain the battery out again.

I guess I'll just bring it to my machanic and have him check it out. Thanks for everyone's help though.

BmW1819 · 08-13-2011, 05:03 PM

nope the resistors short out in the fan assembly there has been cases where they burn up and some cars acutely burned down from this

doogee · 08-14-2011, 08:06 PM

Wrong section. Try E46. They'll know more about it.

Ceeker · 08-14-2011, 08:33 PM

Quote:

Originally Posted by BmW1819

nope the resistors short out in the fan assembly there has been cases where they burn up and some cars acutely burned down from this

so the fan in this model has the resistor built in? Would make sense; I've heard cases where the fan stayed on and burned the whole car down.

BmW1819 · 08-15-2011, 06:58 PM

yea hes in the wrong section this is a e46 fan where there is one fan for the engine/ac