Over several days (now going into weeks) I've been dealing with connection problems between GDU 460 and GNX 375. I originally wired GNX 375 per GNX install instructions. G3X per page 25-27 in install manual Ver AP, AQ, AU shows different wiring config. Will no luck getting RS-232 and ARINC taling between GDU and GNX, two contacts about problem with Garmin G3xpert with modified config settings, I decided to rewire to meet the suggested wiring on G3X to GDU pin outs. Spent today trying to figure out which wires were which, which to cut and which two wires to splice to accomplish the goal.