Don,
The tranny brake wire will be ok. Even if it is a tiny wire to a relay it is still carrying car voltage. The problems come from low current and low voltage carrying wires like for sensors, crank triggers, tachometers, computers etc. Those are mostly low voltage.
I see that you are in Wylie. That is literally right down the street from me. I will preface this to saying that my purpose of being on the internet and helping people is not to be self serving. I have never ever asked anyone for their business.
That said, I could use it if one of you wanted to consider me. I think my phone number is in my profile, if not I will put it there. If my services may not be what you would wish, I can likely point you in a direction of one that may better fit your needs. I am a very small one man no dollar operation. I am not a big famous shop.
972-633-0563
Best time to call is at night.l I work more at night and sleep in the mornings. lol.
Thx,
Ed