I first finish the stick wiring so I can test all the buttons. Despite some dicrepancies in mu schematics, the trim buttons work, as does the autopilot disconnect and the right stick isolation switch.
I then push the transponder fuse and ckeck that the left EFIS sends altitude informations, as does the altitude encoder when the EFIS is off.
I also light up the VHF-NAV, but I can perform only one test as the intercom is not wired. However, I manage to check the COM reception by listening to the traffic at the nearby airport.