GRT Avionics

I am installing the TRIG TT22 remote transponder without the TC20 control head. Pin 13 from the transponder on the wiring diagram goes to the control head for the remote on function. When you don't have the control head the way I read the manual the remote on is active when the power on is pulled Low. I believe that means it is grounded. So if I connect pin 1 - 13 - 14 to frame ground it should work without the control head. Is my thinking correct?

Yes. That way it will always turn on when power is applied. Then it will wait for the EFIS commands to tell it what mode to be in.