Altima Fan Wiring Guide

[Big Bronze Rim]

As many on here have probably seen the ubiquitous SD20DET Fan and Radiator Comparison Test (http://home.satx.rr.com/nissanweb/RadTest/RadTest.htm) that some friends and I conducted a few years ago, you will know that Altima fans make a great budget cooling solution.

I threw this together as I have been asked by a bunch of people how I wired my Altima fans when using a fan controller. I have my fans wired on high speed and are switched on and off by a Greddy MSS. Most fan controllers (HKS and Greddy that I know of, and probably Pivot et al) operate the fan through a switched ground. This is used to control the coil side of a 30A Bosch-style relay.

To wire fans on high speed it is necessary to connect the two seperate coils in each fan using the schematic below. The wire colors are consistent with the Altima fans in my car, however I cannot help you if your wire colors differ from mine. You will have to consult a FSM or experiment as I did. I have also included the plug schematic so that you can reference the wire colors as they are in the plug. The plug for the fan to harness connection is viewed with the wires coming out towards you. As a note, the wires on the car harness side of the Altima fans have different color coding, but should be easy enough to figure out based on the schematic below. Let me know if you have any questions.

http://img.photobucket.com/albums/v102/bdenton180sx/AltimaFanWiringDiagram.jpg

http://img.photobucket.com/albums/v102/bdenton180sx/PlugSchematic.jpg

-Brad

[Pred]

dang man thanks a bunch! I just started doing mine today. I chopped the shit out of the shroud to make it fit flush and now I was wondering which wires were which. You couldnt have helped me any more!

[orion::S14]

Good write-up, thanks for posting wire colors.

My only suggestion would be to use a total of FOUR relays...one for each speed (low and high) on EACH fan.

This way, if you have a relay fail...that fan will still run on low.

The OEM S14 setup has one fan, and two relays...for reliability.

- Brian

[Big Bronze Rim]

I thaught about using 4 relays for low and high operation but since the fan controller I'm using only has 2 channels I had to make a choice. If I had a means to do what you suggested, I would have. I am currently running each fan on a seperate relay, the diagram just depicts one fan. This still gives me a little redundancy.