Servo glitch
 

I have a Tekin rx8 gen2 with the Tekin 2050. I have a Hitec 965mg servo. My runs the rc8 e. Today in a race he reported steering would go away and come back. The BEC wire came undone on the track from the esc so I pulled it from the motor too. Any guidance is appreciated.

You will need to clarify exactly what happened to what wires. For example, there is no BEC wire running to the motor, BEC is what powers the receiver which passes that through to the servo.
That being said, the cause of the servo glitch is likely a loss of BEC input to the servo or output from the ESC altogether.

Ok sensor wire from esc to the rear of a Tekin t8 motor. It came free from the esc and was still plugged into the motor. We have a hitec hs965mg servo I have read about gray outs,but doesn't that usually effect both steerage and throttle control?

I think we need to clear up cogging vs glitching.

If the sensored setup from the motor to the speed control has an issue like a bad or disconnected cable your car will run with a stutter and jerk at low RPM, or may not go at all until it is nudged. Often running OK at the higher RPM if and when you get there. - that is cogging.

Glitching is in effect the electronics rebooting because there is not enough power going through the radio gear. It is most often a combination of a very demanding steering servo, a weak BEC in the speed control and a spektrum receiver ( I use spektrum myself so I am not bashing them, just being honest ). This is addressed with either a glitch buster capacitor that will help to steady out the power so it does not ripple and brown out, or by bypassing the BEC in the speed control (pulling the red middle wire on the ESC plug) and using a third party external BEC instead.

If you are glitching you will get random jitters from the steering servo, you will hear the ESC arm at random times, or you will see the power light go on and off on the receiver. Any or all of these will be an indication of brown outs... with cogging you will have smooth steering and will be limited to throttle issues, mostly at low RPM.

FWIW, you can also get "brown outs" from a bad connector to the battery, if that is the case messing with the wire will cause the issue to happen like when you jiggle it.