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Old 03-29-2016, 10:39 AM   #111
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Note to self: take better and more pictures from many angles of existing wiring before taking it all apart and relying on memory.

Fortuately, I have wiring diagrams, but even those take a while to go through. The little letters and numbers on the wires can get hard to read.
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Old 03-29-2016, 10:57 AM   #112
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That's why I plan on rewiring the electrics. Especially since it doesn't support 2 wire LEDs
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Old 03-29-2016, 11:20 AM   #113
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Speaking of LEDs, scooter, I plan on every last light on the bus, inside and out, being LED. Would it be bad to ground them to the chassis like normal lights?
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Old 03-29-2016, 11:43 AM   #114
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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.
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Old 03-29-2016, 12:00 PM   #115
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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...

-Christopher
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Old 03-29-2016, 12:04 PM   #116
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Speaking of LEDs, scooter, I plan on every last light on the bus, inside and out, being LED. Would it be bad to ground them to the chassis like normal lights?
The tail light's I'd initially gotten had a ground pigtail to use one of the screws for ground. But it shouldn't be too difficult to run a ground wire to chassis
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Old 03-29-2016, 12:13 PM   #117
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I'm definitely paranoid about grounding since before I took everything apart, there were ground wire issues affecting the computers. For ground to the body, chassis and motor, I have taken everything down to the bare metal, used dielectric grease and sealed with multiple coats of paint and rubberized material. I am also cross grounding the body to the frame in several locations.

What is a ground loop?
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Old 03-29-2016, 12:21 PM   #118
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What is a ground loop?
This

And/or

This
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Old 03-29-2016, 12:39 PM   #119
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a ground loop can easily happen if you "spider ground" where you ground aimlessly at various points ..

most often in a vehicle there is a Main ground to the chassis and then the body has a connection to the chassis.. most often then for body systems like lights, heaters, etc.. they get grounded to the body metal itself...

for chassis systems.. (engine, starter, solenoids) they get grounded to the chassis.. sometimes there are shared grounds in the form of engine sensors that go to the computer (newer vehicles).. the computer most often is then one of the grounds you see at the chassis going direct to the main computer..

biody sensors for climate, temperature etc usually have 2 wires.. as they need "reference" ground.. which means their ground '0' needs to be the same as the computer..

in the scenerio i mention, there is only one path to ground for any given point..

when you start running wires everywhere.. there can be m,ore than one path to ground... and also induction can occur creating a non-zero voltage reading from ground-to-ground.. (ie measuring ground in 2 places should always read 0 if all is good).... by that I mean place the red and black leads of your meter on ground at 2 different places in your bus... you should always see 0 volts or very close to it..

a more proper way to "fix" a broken ground would be.. lets say you want to have separate ground for a heater motor.. you wouldnt simply run a new ground to the heater and attach it to the existing ground lug (going to the heater frame).. you would lift(disconnect) the ground wire completely off the frame and connect your new wire to the ground terminal of the motor.. and your new ground would be run back to the central spot or ground-bar where theres still only one possiblke ground path for your motor...

-Christopher
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Old 03-29-2016, 01:03 PM   #120
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I guess I need to read more about it then. I am pretty confused now. Wouldn't all of the existing little ground wires from each and every light cause the "spider" effect and make a loop?

If I add several ground straps from the body to the frame, am I creating a ground loop then?

My thinking was that every piece of metal in the frame and body was basically a giant negative wire, with the return flow essentially taking the most direct route to the negative post of the battery, through bolts and welds and whatnot.
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