The fuse that is inline with the Panel Lights rheostat keeps blowing, but only while the engine is running.  Sitting in the hangar with engine off, a new fuse, there are no problems.  The dimmer works as expected and the post lights and instruments get bright or dim, etc.  But if I start up and start taxiing, the fuse will blow within minutes. I've studied the schematic for my 1982 M20J and I see that the primary load on that fuse is the Radio Lite bus.  All the post lights draw power