Auxiliary Fan

[Rasta]

Can I make a universal electric fan work with the original two speed settings on my '91 318is?

[Jaxx_]

yes, but not easily. how comfortable are you with electrical work? can you wire up relays? can you troubleshoot issues? or can you just do simple red-red and black-black wiring?

[KenC]

You're talking about the condenser fan? Just splice it in. It's the resistor that controls the speed.

[Rasta]

Not an expert at electrical work but I can do most things. The way it is wired right now is the way it was with the oem fan. But I noticed that when I power on the a/c (that's when it should run at low speed) it doesnt work. It hints at moving but it doesn't. When I wire the fan directly to a power source, i.e battery or any positive wire, the fan works fine. I understand that the resistor is what controls the speeds by lowering amps/volts and the problem is the low speed. However the resistor is brand new. I am wondering if, the fan motor itself needs to be two speeds? I am trying to leave it as original as possible but at this time I cannot afford the oem fan. Please share your wisdom

[KenC]

It's a DC fan. It just has one motor and the speed is varied by the voltage applied.

[Rasta]

So what can be done?

[smooth]

If you know that the resister is good then you need to make sure the relay is good, too.

Keep in mind that just because it's new doesn't mean it's good.

[Rasta]

I appreciate averybody's help. Where is the relay? What is a good way to check if it is good?

[immajackuup]

http://m42club.com/forums/showthread.php?p=109866#post109866

[Rasta]

I got it to work. Thank you all!