Originally Posted by SD Blue

Sorry for the delay, Startek finally let me open the diagram pdf!

It's here on page 307: https://www.startekinfo.com/StarTek/outside/12253/program/ETM/ACC83-85.pdf
The Pushbutton Controller powers the Evap. Temp Regulator and then the Compressor Relay. The Compressor Relay engages to power the Low Pressure Cut-out and then the Compressor Clutch.

BTW, ensure you are looking at the correct diagram as there are three different set-ups for this. Also, the Compressor Relay for this model is Relay J. (If you are looking at the Fuse Box, fuses to the left, it will be in the third column of relays from the left and closest to you.
Page 103 shows it here:
https://www.startekinfo.com/StarTek/outside/12253/program/ETM/126td83-85.pdf

IIRC, there was an incident where someone has experienced an overnight power drain from the power antenna. I don't recall if you've checked this or not, but another place to look for that problem.