TCC wiring question

[LeesTruk]

I'm in process of under dash wiring for my LS swap, particularly the brake switch. I'm using a 3 position brake switch (1 n/o, 2 n/c ) from a '96 Firebird/Camaro. The 2 n/c switches will be for TCC and cruise. It's to my understanding that there will be B+ (ign. switched) to both of these switches and from the switches to the TAC (cruise pwr.) and the PCM for TCC. The question is, are these B+ sources for power or just 12v reference signals? Ultimately, the question comes to what gauge wire do I need to run?

I've got two neat factory pigtails that will plug into my fuse block. One looks to be 14 gauge, the other is 18 gauge wire. I'm not sure which to use for my wiring, although it would be safe to err on the larger of the two. Thanks

Lee