Originally Posted by dan-fox
Boy, I wouldn't. Just an opinion from an old guy that used to build electronic chassis before he got seduced by the Dark Side and went to software. I never trust a chassis ground; I always run a black wire back to a known good ground somewhere (like a terminal strip with a big black wire going back to the battery).
That's just me, but it'll nip an especially annoying class of problems in the bud.
I aleways grounbd certain things directly with a wire and other things I allowed to be chassis or body grounded..
on cars i always had a couple body grounds separate of the chassis ground... granted this does run the risk of a ground loop but theoretically if you place a bodyt ground on each side of the body.. (nice and heavy) directly from the grounbd bar and then re-set the main chassis ground you should be good...
that said, I still always discretely ground anything that is computerized or electronic in nature... and then I tested..
say I ground lights, fan motors, and such to the body I would turn everything on and check for ground potential between the battery Minus and the ground point where my major devices are grounded.. I should see negligble voltage... if I see vo,tage i know the ground is not good under load... I also would do the same while driving and make sure i didnt have intermittent grounds as I hit bumps and flexed the car..
granted a bus is much larger and likely much tougher to test.. but the concdept is still similar..
the reason i always grounded all of my computers and el;ectronics the same place.. is that oftentimes those computers share comms loops and such between them.. those comms loops are often voltage sensitive... sensors for say temp, oil pressure, etc i always boiught the 2 wire version as engine grounds are notorious for being bad.. esp if aluminum is involved...