Electrical Engineering advice - 36V auto range ohm meter

Karma for all; thanks for the input. This project was put on a shelf until I could properly contain it (via custom closure). In an attempt to create a smaller footprint, I accidentally read an NRF module tutorial (Robin2's) - which changed my paradigm. The supply pack (without the display), supplies the voltage/current and transmits the resistance readings; the receiver (with the display) informs the lowly field tech (me) of the filed resistance. In this journey, I was challenged to read battery voltage of both transmitter and receiver.

Many thanks for pointing me in the correct direction.