I hate to say it but....book face ....saw a photo recently depicting a jumper installed. A single wire jumping from one terminal to another
I looked and looked even harder when stripping out a 9/84 Sportswagon - no control module above the pedals, behind the cluster at all. Maybe some models or some markets had or required the safety circuit, others not?
Tricky to get to.
Why not 'just' run say an LED in your console powered by the earth and power wires at the pump so you can monitor its power supply??