Auxiliary fan resistor question

[schtozo]

Hi, ive noticed that when i turn on the ac, i dont hear the aux fan kick loud so i suspected that the resistor was bad, (changed two years ago). So i proceed to remove it and jumper all three wires together. That worked great, the fan turns on high with the ac as it used to do. Now my question is: is it harmful to leave the wires jumpered wiith no resistor? Or can i leave it jumpered?

[bmwguy325is]

the wires may get to hot and burn.
But I have jumped the switch before when my fan clutch died on a road trip. It ran no stop for several hours

[MR E30 325is]

The resistor is used to get the fan to run on the low setting. Connecting all three might not be the best of ideas.

[bmwguy325is]

The resistor is used to get the fan to run on the low setting. Connecting all three might not be the best of ideas.

Missed that part good call.........

[TurboJake]

I won't recommend it by any means.
But My A/C Worked great all summer........
I also use my A/C to cool down my car when sitting still for too long.......
I also use my A/C to blow cold air up the womans skirt when she's sleeping and not looking............






(And my resistor has been broken since the day I bought the car)
(And I didn't wire all three together)

[Adrian_Visser]

As long as you use large enough gauge wire it won't be a problem.

[schtozo]

Ok, let me get this straight, the resistor is used to get the fan turn on in the low speed?

Two days ago, when i turned On the ac right upon turning the car cool in the morning, the aux fan used to kick on high. All of a sudden it just didnt want to kick at all, the fuse was fucked so i changed it but the fan didnt want to kick on high, thats where i proceed to jumper the wires together and it worked as before.

There is two red wires and one black, my previous resistor had the two red wires on one end and the black on the other, is that how it was supposed to be? Can someone check for me please?

[cabriodster87]

I have my fan jumped on the rad sensor plug, so i would suspect that is the part to replace.

[ROLLingKING]

i have the same problem with my aux fan..its your sensor plug, MOST LIKELY

I replaced my resistor a couple weeks ago and put in a new one. My fan used to never work and that got it running.

now the problem is the fan just ALWAYS runs on low. i swapped one from the junk yard and that one didnt work at all. try the sensor plug. let me know if it works

[schtozo]

i have the same problem with my aux fan..its your sensor plug, MOST LIKELY

I replaced my resistor a couple weeks ago and put in a new one. My fan used to never work and that got it running.

now the problem is the fan just ALWAYS runs on low. i swapped one from the junk yard and that one didnt work at all. try the sensor plug. let me know if it works

Do you mean the sensor on the right side of the rad? thats 2 years old too. It might be bad as well. Ill check on that after my vacations. Im leaving to bmw heaven in 3 days.

[spdracrm3]

the system is designed to turn the fan on low speed (thru the resistor) any time the AC is switched on(activates low fan relay K1 in fuse box). or thru the cooling fan switch in the upper right of radiator with temp above 196F activates low speed fan relay K1,above 210F activates high speed fan relay K6.

the black wire is power supply to resistor from K1 (low speed),one red wire is power supply thru K6(high speed )spliced to the second red wire that runs to the motor itself . the brown wire is ground to motor.so by tying all together your backfeeding voltage up to K1 relay when fan is on high speed which wont hurt anything .

question is why is your fan on high with a cold engine and AC ,has relay/switch been jumpered/bypassed?

[down_shift13]

You can also place a fuse in between instead of just connecting the wires together. That way if the wire heats up, your fuse will pop and you just have to replace it.

[schtozo]

the system is designed to turn the fan on low speed (thru the resistor) any time the AC is switched on(activates low fan relay K1 in fuse box). or thru the cooling fan switch in the upper right of radiator with temp above 196F activates low speed fan relay K1,above 210F activates high speed fan relay K6.

the black wire is power supply to resistor from K1 (low speed),one red wire is power supply thru K6(high speed )spliced to the second red wire that runs to the motor itself . the brown wire is ground to motor.so by tying all together your backfeeding voltage up to K1 relay when fan is on high speed which wont hurt anything .

question is why is your fan on high with a cold engine and AC ,has relay/switch been jumpered/bypassed?

This is exactly the explanation i wanted to read. There was probably a confusion here. This is how the fan used to act:
1- it didnt turn on with the switch in the on position.
2- it turned on on high speed with the ac on but car cold
3- i think iirc with the ac off it did turn on low and high speeds as it should.

The question here is that why did it used to turn on high speed with the ac on but car cold and all of a sudden everything corrected itself by itself?

Personally i prefer the high speed at all times with ac on, it cools much better on stop and go traffic.

**One more thing, did i have the wires correctly on the resistor? The reds to one end and the black to the other?

[spdracrm3]

dont have any suggestion on why it started working normally, but you did have the resistor wired properly

[polska]

You could bypass the resistor like the guys explain above by wiring the red and black wires together and grounding the brown wire. The fan will run on high at anytime it's activated. If that's what happens, then you've narrowed things down to the resistor. Or just keep it the way it is bypassed.

Some mentioned wiring all three together, but I don't know if that's an effective ground. Maybe someone can explain.