I had to tap raw voltage on my Vipercut 30i for the THC on my OG Crossfire.
The red ground to the earth “clamp” lug and the black to the “gun” lug.
I didn’t find any really good info on the forum for setting this up and thought I’d share my success here. If I am wrong, someone tell me quick and I’ll remove the post. Remember to unplug your machine first and wait about 15 minutes or more for the capacitors to discharge before doing this. The picture was taken looking down at the front of the machine. The bottom of the picture is towards the back the top is the front.