Hi everyone,

I want to wire a couple of fans to pass air through the TMIC during stop and go traffic, and also just to have better IAT in general.
It would be nice if I could wire them to the car directly so that it will start spinning on key startup.

Where could I wire it? Could I just wire it to the front battery connection and ground on the trans mount? Or should I find something to tap into non-engine related? If it comes down to it, I'll run it off a separate powerbank, but I the less I have to think about the better for me.

 

You're going to want to wire it into a relay and fuse. Fans tend to have a rather high draw on startup and wiring it into a fuse and relay will help offset any weird spikes.

You can get a micro relay and holder:

From there, wire it as so:



Micro relay pinout:

Your ground can be virtually anywhere. Find a metal spot, run the wire to it with the appropriate sized ring terminal.

Your constant 12v should be to the battery or something that gets constant 12v.

Your switched 12v source can be tapped into the fusebox on the driver side. Probe to find a fuse that gets powered with key on. Benefit, you are now tapping into a fuse, so if the draw spikes, it pops that fuse. Downside, whatever you tap into will also fail.

Once you have that, you have a few options on tapping into that source:
1. You can ghetto fab it (aka: MiniManAdam it) by stripping the wire back, pulling the fuse, then inserting the wire into the terminal, while pushing the fuse into the socket. While not pretty nor especially good, it will get it done. 100% reversible.
2. Attempt to locate the wire on the fusebox connector and do a vampire crimp on the wire. Less ghetto. 100% reversible.
3. Depin the wire from the connector, cut the terminal, crimp both wires onto a new terminal, reinsert into connector. Best approach, most difficult, most expensive, also not as easy to reverse.

Other option for switched 12v is finding a wire, probing it for switched 12v, vampire crimp it.

Good luck.

 

Thanks alot for the info. I'm not the most electrical savy person so I tried re-drawing what you were saying, so that I can have a better understanding,

The relay on amazon has a wire for 87a, I'm not sure what I'm supposed to do with that one. I think the others makes sense though.

Just clarify, I will need to connect both a constant 12v to the battery (with fuse attached) and also a 12v source from somewhere in the fusebox that is controlled by the ignition?

 

Follow the first image as a reference to wiring. The second image is a reference for the pin location on the micro relay.

But yes 12v constant, with inline fuse, to battery (or something else that gets constant power)

12v switched to what's gets powered when you turn the ignition. Doesn't have to be the fuse box, but that's the cleanest install method. If you wanted to be really creative, you could wire it up to the rear wiper, so you could turn it on/off.

The fan would only be effective at idle or slow speeds anyhow.