I realized this box may be much simpler than I initially thought. The circuit we are looking at may not be inside the tester itself. Electronic switching unit for temperature control is component #9, which is already in the car. For most tests, the battery is also disconnected.

So the question is:
1. Is this box simply a junction that selects the pins that we should test directly without #9 circuit involved?
2. Does this box have a duplicate #9 compenent and we have to include the #9 for the circuit tests? If so, maybe we make a dongle or breakout that let's us test the invidual pins, with the #9 component from the car in the circuit?

__________________
Theseus

Instragram: doss_project
1984 300SD - 930 Blue, OM 617
Murfreesboro, TN

Theseus owned a ship in Greek mythology, and when a part of the ship needed replacing, it was replaced. Eventually, everything was replaced. Is it the same ship? (I own the car of Theseus. )