Whenever I load up either the passenger or the freighter version of the 744, both the Overhead Panel Lights(OPL)and the Glareshield Panel Flood Lights (GPFL)work as expected. However, as I taxi, both the OPLs and GPFLs go out, and I cannot get them to illuminate again. The switches look and sound like they are operating normally.I try to turn them on and off, but to no avail. I noticed this problem appeared shortly after I installed the sound upgrade. Any suggestions?-Donald

what is the light situation outside?What about the power situation (I'm assuming you have enough power as you are taxiing).Did you try hitting L a couple times, see what that does? There are a few options, I'd try them and see what happens.-Brian

sounds like your engine driven generators are not connected and as you release the park brake (and ground power) to taxi and the result is your power supply is disconected,fynn