Failed A and B Lanes and Fuel pumps

During a fuel flow test for certification checks, both lane A and lane B lights went solid. Neither the main fuel pump nor the aux fuel pump could be turned on. I was using the start switch to energize the lanes and accomplished checks on both the main and auxiliary pumps successfully with aircraft level. Fuel flow measured around 45 gallons per hour. I than lowered the tail to about a climb attitude and began the same test. Initially the test on the main pump was successful, but the problem occurred when I switched off the main pump and switched on the aux pump. Both lane lights came on solid and neither pump will run when switched on. Tried using the battery backup instead of the start switch with no success. All the fuses in the fuse box are lit and seemed okay. I cannot figure what has caused the problem, nor the fix. All the tests were conducted with the fuel line disconected after the pumps before the fuel rail discharging into a measurement container. This is a new engine that has previously been run numerous times in this new installation. Appreciate your thoughts and help.