Brief Description: Buss Short Troubleshoot / Panel Lettering
In the last session when I wired the DT-50 I was checking the small 4 pin connector on the small harness that is provided with the unit. When I touched the ground and USB/Backlight terminal with the probes I got continuity. I was checking to see if the connector had a short or not since it was a small connector and potentially may have a manufacture defect.
I began to probe further and ended up finding that the continuity between ground block and the fuse block Buss A and Buss B. Well that won't work on an electrical system. I began by checking if one of the power wires for anything was shorting against the fuselage somewhere....nothing! I thought since I put the Fuse-Relay panel on that perhaps there was a ground wire shorting behind the fuse block although I was very careful to be certain there wasn't. I began dismantling the cover for the bay and pulled it away from the airframe.....still shorting.
Ok....must be backfeeding from a circuit. Pulled out all the fuses......short disappeared. I took a fuse and began inserting it in one slot at a time. Fortunately on fuse position #4 the short came back. That was the fuse for the GMU-11. I climbed out of the cockpit and went to the left side where the coil of wire for the GMU-11 run was waiting for the wings to be installed. Sure enough I had shrunk wrapped the pins that AFS had put on to run the wires easier without the pins hanging up....alll power and ground pins were touching....mystery solved. Removed the shrink and problem gone. I did a little label repair since I had removed the panel and put it all back together! Learned a lesson in the process!
