Ok well I think I have it figured out. I'll have a revised version tonight.

In the meantime everyone disregard my botched diagram above.

 

Powerpoint is nice to make wiring diagrams in if you don't have visio or a real drawing software.

 

I have Adobe Illustrator

 

You fancy, huh?

 

Okay Atomic. Here's a revised version let me know what you think.

To add to the confusion I made the master arm switch arm the purge too.

I think I got the position of the IAT relay correct now. Also if I'm reading correctly did you say there is no reason for the IAT to have the resistor just let the circuit be broken and the computer will default to the lowest temp in HP tuners?

 

See attached picture. No you don't need the resistor deal, just have it open when the relay flips and it will default to the lowest temp. Might throw a code, but it will go away when the nitrous turns off. Its not a recommended thing to do on a SD tune.

 

Thanks. You're the man. Only difference is I plan on running a momentary for the purge switch, so there is no ground. But the diagram still applies. Thanks again. I'm just gonna remove mine cuz its garbage compared to yours haha.

 

Yea I figured you would use a momentary, but if it has an LED you will still need a ground for it.

 

Good point. Thanks again.
I'm sure I will still have questions along the way

One I can think of is...
Does my main battery connection going to the NX and Purge relays need an inline fuse?

 

It wouldn't hurt...also one between the Switched 12v and the Master arm switch and between the Switched 12v and Purge switch as well.