2000 323i fan NOT working

[c0wb0ychris]

This is the first trouble shooting form that i am attempting so bare with me yall.

The car is a 2000 323i, and the fan does not work, which is driving me nuts...the LAST thing I want to do is over heat my car, especially with summer quickly sneaking up us.

So, here's what I have done.
1) Bought a new fan, tested it before I put it in the car, worked great. Installed it...didn't work.
2) Tested the voltage coming to the fan from the sensor (on right side of fan near the top of fan)...read normal.

So, we have voltage coming to the fan! Good. My next train of thought (because I have no idea how many more sensors and relays these dang BMW have) is the computer is not sending the signal to turn the fan on. Possible but hopefully not the case.

I work so i'll be off work most everyday at 5pm, so any discussions tonight and any night will be tested the following day and will be recorded here the same night.

Insight please and thanks!

[this1guyshorty]

When you test the fan, was the car still warm?
This could had triggered the fan to work. And after a few hrs of being cool, it may had not turn the fan on.
Check the temp sensor on the bottom hose.
Or check for a bad ground.

[c0wb0ychris]

When you test the fan, was the car still warm?
This could had triggered the fan to work. And after a few hrs of being cool, it may had not turn the fan on.
Check the temp sensor on the bottom hose.
Or check for a bad ground.

We tested the fan outside of the car before it was ever put in. As well, we tested the original fan when it was uninstalled and it also worked fine.

We have replaced the temp sensor at the bottom radiator hose, so i've eliminated that possibility.

Does anyone know, is there anymore relays or sensors that could possibly affect my fan?

[stickbuilder]

Is this car automatic or manual? There is a module on top of the radiator ( passenger side ) that is connected to the fan as well.

[dopey88]

I just had the same problem do this crank the ac the fan should go into low speed now unplug the sensor on the bottom hose and the fan should go to go high speed. If that all works then you are fine also you might want to burp your coolant system that can cause faults too

[mdfiasco]

The term for removing air from any system is 'bleeding'.

This isn't e46fanatics.

OP, test your fan by running the car w/ the AC compressor running. Post results.

[c0wb0ychris]

Is this car automatic or manual? There is a module on top of the radiator ( passenger side ) that is connected to the fan as well.

The car is manual. Yes that's the connector that i've test for voltage and it read 12V which is perfect.

[c0wb0ychris]

The term for removing air from any system is 'bleeding'.

This isn't e46fanatics.

OP, test your fan by running the car w/ the AC compressor running. Post results.

By AC compressor running, you mean simply by turning the AC on full blast at as low temp as it can go? Tried that, fan still doesn't turn.

[c0wb0ychris]

It seems to me as if the computer is not sending the signal to the fan to kick it on. But i'm trying to rule that possibility out until every other option is bled out...

[mdfiasco]

By AC compressor running, you mean simply by turning the AC on full blast at as low temp as it can go? Tried that, fan still doesn't turn.

Full blast or not, it simply needs to on and working correctly.

In regards to the fan switch module: You're receiving 12 volts on the leads that provide power to your fan? You're testing this on the module (the black box on top of your new fan) ?

[c0wb0ychris]

I just had the same problem do this crank the ac the fan should go into low speed now unplug the sensor on the bottom hose and the fan should go to go high speed. If that all works then you are fine also you might want to burp your coolant system that can cause faults too

Even if I do turn the AC on, the fan still does not come on. I will try turning the AC on and then disconnecting the lower sensor, but i'm afraid is most likely not going to have an affect.

One thing I did fail to mention, is my AC system does have a leak in it and there is NO refrigerant in the whole system. Are yall saying that this could be the root cause of the possible "fan failure"?

[c0wb0ychris]

Full blast or not, it simply needs to on and working correctly.

In regards to the fan switch module: You're receiving 12 volts on the leads that provide power to your fan? You're testing this on the module (the black box on top of your new fan) ?

Correct. The black box/ plug in receives 12 volts

[mdfiasco]

the way this reads is this:

the copper wire that physically leads to the motor phycically located on the fan is definitely receiving 12 volts, yet it's not operating.

[c0wb0ychris]

the way this reads is this:

the copper wire that physically leads to the motor phycically located on the fan is definitely receiving 12 volts, yet it's not operating.

Ummm assuming we are both speaking of the same connector/block box, then correct.

To help clarify: The connector on the top "right" side of the fan (viewing left and right from the true view point of an engine, from inside the car) meaning passenger side. I unplug this connector and test the volt reading here, the side from which the power is coming from (not the fan itself). I believe this part is the female connector.

[mdfiasco]

that's pretty weird. Science tells us that 12 volts should fire that thing up. However, there may be some special info needed for the brainbox on the fan to fire up. This is a problem for the Bentley manual, which I do not have on me at the moment.

[KillerSE7EN]

some thoughts

Could be:
Temp sensor in the radiator
Fan relay
Improper cooling/ system issue
ECM issue

If the fan works when you put it to a battery, there is obviously something stopping it from turning on. You need to go through the system one by one. I personally would bypass the relay by jumping the pins. You can also remove the relay and put 12v to it and see if it clicks

[c0wb0ychris]

that's pretty weird. Science tells us that 12 volts should fire that thing up. However, there may be some special info needed for the brainbox on the fan to fire up. This is a problem for the Bentley manual, which I do not have on me at the moment.

No worries, I appreciate your help.

One thing I am going to try this weekend, because it seems to be a reoccurring thought, find the cooling leak and fix it then recharge the AC so that it's back and working properly. This could be the root cause of my fan "failure" (I hope).

I will get back to yall about this ASAP. More insight and trouble shooting tips are still welcome!

[c0wb0ychris]

UPDATE: Today we tried to find the leak in the AC system. There is some refrigerant left in the system, which we figured with a leak all would bleed out eventually. But we are still unable to put refrigerant into the system. Maybe because we do not have high enough pressure in the system to engage the compressor clutch.

Is there a way we can jump the compressor to engage the clutch?

[c0wb0ychris]

UPDATE:

Turns out the circuit coming from the computer to the fan has burnt out....I had to put a mechanical fan on from an automatic bmw. I could replace the computer to put back the original electrical fan but i've heard prices are about $1200 for a new one. Maybe later on down the road i'll take on that project, not now.

As for the AC, the compressor was bad. The "pop" and leaking of refrigerant came from the relieve valve on the compressor (I had no idea there was one). Tomorrow the AC will be recharged and back working.

Glad to say all is fixed! Still bummed about the mechanical fan but hey, at least my cooling system is working now!

Thanks for everyone's help and suggestions.

[dcasper]

UPDATE:

Turns out the circuit coming from the computer to the fan has burnt out....I had to put a mechanical fan on from an automatic bmw. I could replace the computer to put back the original electrical fan but i've heard prices are about $1200 for a new one. Maybe later on down the road i'll take on that project, not now.



As for the AC, the compressor was bad. The "pop" and leaking of refrigerant came from the relieve valve on the compressor (I had no idea there was one). Tomorrow the AC will be recharged and back working.

Glad to say all is fixed! Still bummed about the mechanical fan but hey, at least my cooling system is working now!

Thanks for everyone's help and suggestions.

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witch fan did you buy? I am having the same problem and have replaced the fan relays etc