Tekin Rs setup cutting out

[TMRdevelopment]

Running an RS Pro with Redline motor in my boys 2wd. It runs for around 5 seconds then judders and glitches before cutting out, going again briefly after a few seconds. If I turn it off and on it does the same.

Tried my own radio gear and same issue, but noticed with my handset it brought up the low battery voltage warning on the radio when i pressed the trigger or turn the wheel. WEIRD! It seems like the speedo is maybe killing the radio gear somehow?

Any ideas?