AV-8B harness repair that keeps tripping people up

I was helping a buddy troubleshoot a nav system fault last Thursday on a Harrier. Three other guys had already looked at it and swapped the box. Turned out someone had repaired a chafed wire in the harness but used the wrong gauge replacement. The resistance difference was small but enough to mess with the signal. Has anyone else run into issues from mismatched wire gauges in critical harness repairs?

3 comments

3 Comments

the_mila27d ago

Shoot, that reminds me of the time I tried fixing a wiring issue on my old truck and used speaker wire because it was what I had in the glovebox. Let's just say smoke makes for a bad smell in the cab. I learned real quick that even a tiny difference in wire size can throw everything off, like you said with that Harrier signal. People don't think about the resistance changing just because the wire chunk looks close enough. Have you ever checked the gauge chart before cutting or do you just eyeball it?

sageadams27d ago

Applies to everything - eyeballing never ends well, I always check specs twice now.

carter.gavin12d ago

Man I've definitely been there. My "close enough" wiring job on a trailer light kit ended up with the turn signals flashing the brake lights instead.