Is there a way to wire the auxillary fan to be on high? a/c pressures high

[clydesdale]

I need more cooling form my condensor. Is there a way to make the fan come on high?

[Dj Buttchug]

yes but you need a two speed fan.

[StereoInstaller1]

yes but you need a two speed fan.

All E30s have "2 speed" fans...except there is no such thing as a 2 speed fan.

There is a resistor that drops the voltage down to about 9V on "normal". Bypass that resistor is one way to do it.

[clydesdale]

I was able to jumper the wires at the thermo switch on the radiator and confirm that both high and low speeds work. Can you provide me with a little more info on where the resistor is and how to bypass it? Thanks and I greatly appreciate your help. I am trying to see if better airflow will help my a/c retrofit.

[StereoInstaller1]

Well, I found it on the diagram...but if you hook the high speed and low speed together, you will only have high, if that is your goal.

[e304me]

I'm quite sure the fan does come one high when the AC is on

[Gnarles]

If you bypass the resistor, you will probably need a large amp fuse.

[twistednut]

Did it on my son's car. Two wires, one to the common of the thermo switch and one to the high side of the thermo switch. Ran them to a spare fog light switch mounted above the radio. Press the switch when extra cooling is needed.

[StereoInstaller1]

I'm quite sure the fan does come one high when the AC is on

You must not have the diagram, or maybe you don't know how to read it. BMW diagrams are kinda tough.

A/C only connects to the "Normal Speed" (not high speed) circuit.

If you bypass the resistor, you will probably need a large amp fuse.

Huh? Why would you think that? The fan circuit is fused in 2 places already, it has plenty of protection.

Luke

[Gnarles]

I'm pretty sure the low speed fan circuit has a lower amperage fuse than the high speed. When you decrease the resistance, you effectively increase the current draw most likely requiring a fuse with a higher amperage rating.

[StereoInstaller1]

I'm pretty sure the low speed fan circuit has a lower amperage fuse than the high speed. When you decrease the resistance, you effectively increase the current draw most likely requiring a fuse with a higher amperage rating.

Yes, true, but if he crosses the input wires, that is no longer an issue, as the output of the relay goes to the fuse before the fan or the resistor.

So yeah, the high speed uses a 30A, the low speed uses a 15A...but the high speed will be powering the fan, so no worries.

[NC325iC]

i wired it up in the fuse box to do that its pretty simple actually you just have to tap a spade connector

[clydesdale]

Here is something that I copied off of an old post by "Netcsk" from the following thread:

http://www.r3vlimited.com/board/showthread.php?t=109450&highlight=fan

Here is the specific post:

"Very cool. Thanks for the pictures and explanation.

I decided to try the fan on high speed. Wow. It is very loud.

I looked at the diagram and decided that K1 and K6 connected via terminal 87 would kick the high speed fan on via the A/C and the thermo switch. I just had to remove fuse 3 (only for the aux. fan low speed) so that I wouldn't be running the circuit for no reason.

Feels like much more output from the fan. Hopefully that will do the trick. Even more so, I hope the fan was designed to run full speed continuously. I guess I will find out".



So, do I just stick a wire in each of the "87" terminals in the box under each relay and then stick the relay back in. This would sandwhich the wires in place and jump both K1 and K6 together. These are the relays that control the fan. But, is this done with just a jumper wire like I described? Thanks.



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[StereoInstaller1]

Jeez, seems a tough way to do it.

[clydesdale]

I can't tell if you are joking. It seems really easy in theory. Stick wire in the blade of each relay and pull one fuse. Does that sound like an ok plan? How else would you suggest? Thanks.