Vehicle electrical grounding

WrenchMonkey · 08-22-2018, 06:43 PM

I'm running some 0g cable from the battery on my Burb to the back, to run a small inverter inside, and eventually a small trailer winch.

It's got the stupid low-profile side lugs on the battery, so the positives all come off a separate distribution block, and the negative is grounded to (I think) the engine block.

Should I run a separate 0g ground cable all the way back up, as close to the battery as I can? Or just ground it to the rear of the frame, since the frame will have 10x the cross section that the cable does?

The shortcut will obviously be easier, but I've already bought the cable, so there's no extra expense at this point...

93 Krawler · 08-23-2018, 04:45 PM

On my rig, the 4/0 neg for the winch was grounded to the body. But it also has a 4/0 ground from the battery to the frame.
When i put the quick disconnect on my van for my inverter, i cut the plastic cover to the side connection on the battery a little so i could fit the end of the cables on behind. You can remove the little bolt on those and use a 3/8 bolt. I had to trim mine down some so it wouldn't bottom out. Way easier to tighten up than that 8mm head too.

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WrenchMonkey · 08-23-2018, 04:46 PM

Further research, and talking to an electrician, says my theory is good: The frame itself is probably a better conductor than the 0g grounding cable.

The problem is, how is the frame grounded back to the battery? If the battery is jumped to the block, and the block to the body, and the body to the frame, how big are all those individual jumpers, and how good are all those connections?

To make it work, I would have to run a solid ground from the frame back to the battery, and at that point, it'll be easier just to run a cable the full length.

WrenchMonkey · 08-23-2018, 04:49 PM

Quote:

Originally Posted by 93 Krawler

On my rig, the 4/0 neg for the winch was grounded to the body. But it also has a 4/0 ground from the battery to the frame.

Ha, just what I was saying...

Quote:

Originally Posted by 93 Krawler

You can remove the little bolt on those and use a 3/8 bolt. I had to trim mine down some so it wouldn't bottom out. Way easier to tighten up than that 8mm head too.

I need to look at that. I don't have much room to work with, but I'd like something better like that.

blazerbrad · 08-23-2018, 05:58 PM

I use a 3/8" stud that is screwed into the battery terminal and then a nut to hold the cables on. That way you don't have to worry about the bolt being too long or too short. But of course this usually requires a little more clearance around the terminals and if yours is set up like my truck there is not a lot of room.

Regarding grounding the battery to the frame, i would think it would be easier to run the couple of feet between the battery and straight down to the frame versus running a cable all the way from the back up to the battery.

jeepmanjeff · 08-24-2018, 10:16 AM

you can also use a junction post to place all the grounds together for one nice easy setup. Here is where I bought my electrical items from. Great to work with and fast shipping

http://www.texasindustrialelectric.c...ion_blocks.asp

WrenchMonkey · 08-28-2018, 06:27 PM

Quote:

Originally Posted by 93 Krawler

You can remove the little bolt on those and use a 3/8 bolt...

You were right, and that's exactly what I did. I had to cut the rubber insulation off the factory cable end (like you did, but more) and then it all bolted up great.

Fuse holder on the battery itself, then ran both cables straight back together, along the framerail. Out between the body and the rear bumper, and velcro'd the plug in place. With the door shut, it's really well protected and almost invisible.

Thanks for the help guys!

WrenchMonkey · 08-29-2018, 08:49 PM

Hot meals this weekend!

93 Krawler · 08-29-2018, 10:00 PM

Quote:

Originally Posted by WrenchMonkey

Hot meals this weekend!

Sweet!

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Smiddy24 · 08-30-2018, 08:15 AM

Quote:

Originally Posted by wrenchmonkey

hot meals this weekend!

nice!

08-22-2018, 06:43 PM	#1
WrenchMonkey Mechanical Animal - CORE Member - - Moderator - Join Date: Feb 2008 Location: Beechmont Posts: 1,883	Vehicle electrical grounding I'm running some 0g cable from the battery on my Burb to the back, to run a small inverter inside, and eventually a small trailer winch. It's got the stupid low-profile side lugs on the battery, so the positives all come off a separate distribution block, and the negative is grounded to (I think) the engine block. Should I run a separate 0g ground cable all the way back up, as close to the battery as I can? Or just ground it to the rear of the frame, since the frame will have 10x the cross section that the cable does? The shortcut will obviously be easier, but I've already bought the cable, so there's no extra expense at this point... __________________ DIRTY DEEDS, DONE DIRT CHEAP Whatever doesn't kill you makes you stranger

08-23-2018, 04:45 PM	#2
93 Krawler >>>PMC<<< - CORE Member - - Administrator - Join Date: Sep 2010 Location: Ross, OH Posts: 2,069 Images: 1268	On my rig, the 4/0 neg for the winch was grounded to the body. But it also has a 4/0 ground from the battery to the frame. When i put the quick disconnect on my van for my inverter, i cut the plastic cover to the side connection on the battery a little so i could fit the end of the cables on behind. You can remove the little bolt on those and use a 3/8 bolt. I had to trim mine down some so it wouldn't bottom out. Way easier to tighten up than that 8mm head too. Sent from my SM-G930V using Tapatalk

08-23-2018, 04:46 PM	#3
WrenchMonkey Mechanical Animal - CORE Member - - Moderator - Join Date: Feb 2008 Location: Beechmont Posts: 1,883	Further research, and talking to an electrician, says my theory is good: The frame itself is probably a better conductor than the 0g grounding cable. The problem is, how is the frame grounded back to the battery? If the battery is jumped to the block, and the block to the body, and the body to the frame, how big are all those individual jumpers, and how good are all those connections? To make it work, I would have to run a solid ground from the frame back to the battery, and at that point, it'll be easier just to run a cable the full length. __________________ DIRTY DEEDS, DONE DIRT CHEAP Whatever doesn't kill you makes you stranger

08-24-2018, 10:16 AM	#6
jeepmanjeff Ah Unz ze President! - CORE Member - - Moderator - Join Date: Jan 2007 Location: Fairfield Ohio Posts: 588 Images: 343	you can also use a junction post to place all the grounds together for one nice easy setup. Here is where I bought my electrical items from. Great to work with and fast shipping http://www.texasindustrialelectric.c...ion_blocks.asp __________________ Keep them on all 4's

08-29-2018, 08:49 PM	#8
WrenchMonkey Mechanical Animal - CORE Member - - Moderator - Join Date: Feb 2008 Location: Beechmont Posts: 1,883	Hot meals this weekend! Attached Thumbnails __________________ DIRTY DEEDS, DONE DIRT CHEAP Whatever doesn't kill you makes you stranger

08-23-2018, 05:58 PM	#5
blazerbrad - CORE Member - Join Date: Feb 2007 Posts: 831 Images: 6	I use a 3/8" stud that is screwed into the battery terminal and then a nut to hold the cables on. That way you don't have to worry about the bolt being too long or too short. But of course this usually requires a little more clearance around the terminals and if yours is set up like my truck there is not a lot of room. Regarding grounding the battery to the frame, i would think it would be easier to run the couple of feet between the battery and straight down to the frame versus running a cable all the way from the back up to the battery.