Cummins C Series mechanical Beede inst panels

just installed factory reman C series with basic Cummins supplied dual Beede gauge panels. They re connected to the engine harness with a Y cable, one side being marked as master

Trying to figure out why both keys have to be turned on (PH and FB) for the engines to be started. If the FB is off, they will crank from the PH but shutdown as soon as key is release. If starting from the FB, the panels won't turn on unless the PH keys are on. That I can live with but having to go upstairs to turn on the keys to fire them from the PH makes no sense.

Anybody seen this?