I can no longer use OEM style fans due to clearance issues. So I got a slim fan. It has 2 wires only. Both stock fans have 3-wires each...

What is the best way to wire in a single 2-wire fan instead of 2 3-wire OEM ones?

 

3 wires? That's really wierd - do you know where to get a wiring diagram for the oem fans?

If not, you can use an ohm-meter to check where the connections are going to. Find the two terminals on your old batteries that are connected and appear to have around 100ohms (or less) between them. These will be the wire windings for the fan. Just make sure the resistance is not really really small as that would indicate that the lines are shorted. Once you know which two connect to the windings, just wire up the new ones in place of those.

I really should mention that I have no idea what the 3rd wire would be for in a fan, unless these fans have some sort of feedback to indicate their speed or something else. I can't find a wiring diagram for the two oem fans so i'm just going off my gut. If you know where one is to verify this, that'd be great. let me know

 

Each fan has 2 speeds. There are like 6 different modes for two OEM fans depending on the vehicle speed, AC on/off, water temp, ect. The 3 wires on each fan are to allow the fans to operate at 2 different speeds depending on conditions.

 

Just run it off the high speed Alex or off of a switch.

 

Ok, and what would be which wire?

 

Well I would measure the voltage as the coolant hits 96c you should get an indication of which wire is turning the fans on.

 

I had the C&R radiator on my WRX wagon and it only had two wires as well. The C&R had black and blue wires only and I ran the stock black and blue wires to those. Whatever the third stock color was, I left it taped off. I would assume the black was the ground.

Wiring it this way, the fans would come on for the low or high speed signal from the ECU, which is what you want.