So my G35 has been having overheating issues for about 2 weeks and living in Miami, I figured it was just extremely hot. It would overheat when idle but temps would drop back down when driving.

Well on Friday I was stuck in crazy traffic & the radiator ended up cracking and spilling coolant everywhere. I towed the car home & installed a new radiator the next day. When installing the radiator I noticed that the driver side radiator fan had the connector cut off completely near the bottom of the car so that was weird to me. The passenger fan works with the AC & I’m assuming the driver fan is for the coolant. If that never turns on I’m sure the car would overheat. Now I looked for the cable ends where it got cut off at but I couldn’t find it.

My question is this, Is it possible to run my driver side fan off the battery using a switch and manually control it? I have the plug that goes directly into the driver side fan but it has 4 cables. A blue, green, yellow & black wire. Not sure how to go about this. I’ve looked online and couldn’t find this anywhere.

 

That fan operates on low and high speed, depending on the engine temp. U could wire it up and run it manually, but thats probably a lot more work than finding the original wires and hooking it up the way its supposed to be.

 

Both fans should run at the same time, just low or high speed. There is a sub-harness that splits to meet both the fan motors from the main harness, maybe someone plugged it in incorrectly which is why you only have one fan running (?)
You can wire wire in an a manual switch, just make sure you use relays to wire it. Fans pull a bit of current! Two of those wires are for the hi/lo functions of the fan, one is a ground, and the other I'm not sure.
Make sure you properly bleed the cooling system, as these cars like to get an air pocket in the heater core circuit, especially when filling the engine with coolant. Follow the FSM to properly fill! I feel like this is too often overlooked by novice G/Z owners...

 

Thanks for your response Scorpi0, I jacked up the car and found a cable hanging that I’m sure matches up with the 4 color coded cables on my driver side fan. I’m going to find some wire of the same gage and splice them together and see if that fixes my issue, that way I won’t have to set it up on a switch hopefully. I love how your G35 is coming along by the way. That wrap came out sick!

Hey Andrew, thanks for the response. I ended up finding where the harness starts hopefully so I’m going to splice them together with same gage wire and hope that it solves all my issues. When I filled the car with coolant I made sure to unscrew the bleeder valve and get some air out. My neighbor also has one of those elevated funnels that helps burp the system so I used that as well. Turns out I have a super small leak on one of the small hoses connected to the bleeder valve. I ordered an OEM bleeder valve & will be replacing it when it arrives tomorrow. Ill also be splicing the wires for the fan tomorrow. Fingers crossed! Thanks again!