Thread: Fan wiring question

I'm busy wiring them up so that they work via a relay and only off of a temp sensor which will go in the upper radiator hose.

Here's a pic showing the wiring on the OEM fans. Why does the fan have 4 wires? I was expecting 2 a positive and a negative only?

Can anyone shine some light on this please?

wow, never seen that before on OEM fans. It is usually positive and negative

What car is this? It might be a high and low speed but i am not sure.

This is off my N14. It has 2 fans, both have the 4 wires on them.

I know the one fan comes on immediately when the A/C is switched on, so that could explain the extra wires on the one fan, but it doesn't make too much sense to have it on the other one then also.

The 2-speed suggestion seems like a possibility. The aftermarket temp switch I'm going to fit now is also two speed, but it still only has 2 pin outs.

Is there maybe a way to use a multimeter to test which wires are + and which are - (given that I already disconnected the ECU etc)

they are 2speed fans and i think blk and yellow are grounds, i had a diagram in the garage the other day and cant find it now

this should help ya
Altima Fan Wiring Guide - FreshAlloy.com Forums

out of curosity did the car come with eletric fans???

Thanks for the link. The diagrams seem perfect for the 4 wire setup.

And to answer your question, yeah these are the OEM fans on the car. All FWD cars come with electric fans don't they?These really push a lot of air. I'm just changing the wiring as I've gone full aftermarket engine management on the motor.

Thanks again for the info.

cool thats what i was wondering

Automatics came with dual speed fans due to the tranny cooler. Manuals just have single speed. Go over to sr20forum.com and read my radiator fan manual override article if you need help.

Thanks for the hint toolapcfan. I had a look at your thread, just have some questions regarding using the A/C switch to switch the fans on.

How I have my fans wired so far:
Aftermarket Relay with
87 on battery 12v+
30 gives power to both fans.
85 to ignition 12v+
86 runs to the 2-speed vw temp sensor, which grounds when it reaches it's set temperature/s
Both fans grounded on battery negative terminal

So this is fine for a closed loop system. Only I want to now add a manual switch to turn the fans on as and when I feel like it. And I think the AC switch is perfect for this.

Do I need to rewire the AC switch entirely? or do I just connect the wire with the small plug on it (that usually plugs into the AC pump itself) and tap it into the ground wire (86 on my relay) before the Temp switch?

What I'm trying to explain above:



Just need an answer to my queastion above regarding the ac switch. Is the wire that runs to the ac compressor the ground wire form the switch? i.e. can I use it directly as the ground as it is right there?