Sounds as if you want to use the TSX3 in place of the freezer controller. This will require significant wiring changes from the freezer junction
to the TSX3 controller.
Slightly different controller, but did you see this discussion?
https://www.homebrewtalk.com/threads/wiring-and-programming-tsx3.255000/
You will need to make sure the TSX3 parameters are set to support your setup.
I can't make a drawing but here are the wiring pin connections from TSX3 to Freezer harness.
Probe input for temp (assuming freezer thermistor is compatible)
pin 1 -> std1 (3)
pin 2 -> 4 May need different temp sensor as this may need to be unpowered input
pin 7 -> 5 Senses door open when door switch is closed
Power neutral pin 8 -> 6
Power Line pin 2 -> 7 and 9
pin 3 -> 8 Compressor and fan
pin 4 -> 10 Defrost (You will need to program the behavior you want)
pin 5 -> 11 Light (program this relay for light)
TSX3 Power 6 and 7 may need swapped since I don't have enough information on the wiring.
This would be a major project to do and
@day_trippr has the more common simple answer above.
You could also follow the other link I referred to above and use out1 (8) on your controller and 6,7, and 9 along with the temp input which will follow their drawing.