OK here it goes.......
Been running a Traxxas Rustler with Novak 5800 SS, spektrum pro receiver, JR 9100T servo,AMB transponder and Protek 5000 35C 2s lipo for a couple months now and have had NO issues and all has been great sooooooooo....

Got the bug and got a NEW castle Sidewinder 5700 system and installed it friday, set-up and calibration was a breeze, ran it up and down the street in front of the house friday night for a few minutes and put it away for saturdays racing.

Get to the track saturday, trying to run a pack and the on-off switch keeps turning off, played with it for awhile(3-laps ) and finally cut the switch off and soldered the ends together, No biggie one less thing to malfunction.

Went out to finish up the pack and whenever I turn it glitches(like the power turns off) momentarily and then it comes back on, I brought it in, checked it out and here is what I found.............

When I turn the transponder light will flicker and the esc/receiver will momentarily stop/start, I put another battery in that I KNOW is charged........ same thing, Changed the servo to a known GOOD servo..... same thing. Ok finally I swapped the receiver from my 1/8 scale and it does the same thing. I also unplugged the transponder.....same thing....
Its only when I am in a turn, I backed the epa way off just to make sure there isnt a stalling issue with the servo so the servo is NOT being stalled, I have swapped batteries, receiver,servo and unplugged the transponder and yes the batteries are good........ What could it be,

Its like the esc isnt giving the receiver enough power

I dunno...... Im kinda stuck because I already sold the novak that was running flawlessly........

Sounds like you are really stuck since you cut the wires too.
Sounds like you pretty much have it figured out though, you tried replacing all the other components with known good ones, and you know your battery is good. See if a friend will let you try his speed control.