It makes the TC lock similar to having the clutch out on a man- there's no "slip" , allowing all power through the tc like it's one piece. It's been known to cut ets anywhere from .1 to .3 seconds(I consistently run a quarter second quicker when locked), but the real performance benefit is from the weight savings. As soon as you start w/the TCC switch even if your trans doesn't blow from the launches , the lockup, or the heat; you'll want more.
Now take all the money you have, some you don't and some you'll never see. Send all this to your trans guy of choice(follow people's suggestions here) and start looking for the biggest trans cooler you can find.With no money you won't be eating much-no time anyway, you gotta do a trans- and selling the CD player and amp out of your truck will help cover the $, and further the weight savings.
To me, that's what a TCC switch does. A whole bunch.
As for needing a light to know TC is locked- it's not so much so I don't leave it on, it's so I don't forget to flip it at the starting line.
I was unaware the TCC wire at the ALDL has voltage on it- I thought it just carried a ground to the sol., locking the TC.
A relay is a good idea, but with a bed mounted batt. and all my wiring already done to dual underhood relays for my SMC and laptop charger/future Apex-i boost controller, and my trans cooler and fuel pump relays in the bed I don't need to add any more stuff. I'd rather wire it up w/o bringing any more wires through the firewall seeing as how all I need to add is a switched ground. Found a 4 pole illuminated, isolated toggle switch. ! wire to TCC, 1 wire to grd(prolly 16ga.)then 1 low current wire to an ign. on batt. source, and the last wire to ground(not tied to other grd. wire).TaDaaa!
Jeremy