Battery cable and disconnect questions (1 Viewer)

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jfrench

jfrench

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I'm redoing my battery cables. Partly to address this cracked terminal but also just because I want to clean things up and do new boots, etc.
IMG_1396.jpg

What is the point of the ground (pictured below) going both to the engine and to the fender? Can I get rid of the fender ground?
IMG_1395.jpg

I'm also looking for clean install ideas for a battery disconnect if anybody has some? Is it preferable to use a disconnect on the ground cable or the low side battery to high side battery cable (if that's even advisable)?

Thanks
 
Don't remove your body ground. You want a dedicated body ground. And, obviously you want the engine ground.

I prefer my shutoffs on the positive sides of my batteries when I use them. Preferably very close to the battery. I wouldn't do only one battery on a 24V system. You want the entire power system disconnected if you are doing it. Think of it as an all or nothing type of setup. 12V accidentally getting to your 24V systems isn't going to do you any favors.
I am not using shutoffs on my Toyota. Yet. I always seem to end up with them. But, I have a couple on my Land Rovers usually. I put a cutoff on my winch always. That is something that doesn't get used much and could save you arc welding a cable if it rubs through while you are going down the road. It's not a pleasant experience, things tend to get interesting when an 0 gauge cable goes straight to a body panel. It will still do it with the cutoff, but you literally have you hand on it when it happens. So, the response time is much better than while in motion.
 
Nas90tdi said:
I prefer my shutoffs on the positive sides of my batteries when I use them. Preferably very close to the battery. I wouldn't do only one battery on a 24V system. You want the entire power system disconnected if you are doing it. Think of it as an all or nothing type of setup. 12V accidentally getting to your 24V systems isn't going to do you any favors.
I put a cutoff on my winch always.
Click to expand...
Forgive me if I'm an idiot but whether the disconnect is on the ground cable, between batteries or on the positive side, does it not accomplish the same goal? On the ground cable it takes the ground away from the whole system. Between batteries it leaves the low side battery supplying 12v to nothing but the disconnect, which won't do any parasitic draining of the battery, and the high side battery without a ground. On the positive side it cuts parasitic draws and makes the starter inoperable. Putting a disconnect on the positive side requires that it be placed between the battery and the cable to the starter as well as wiring harness, which I guess is easy enough, there's just not a lot of real estate there for a clean install. The negative side doesn't have much real estate either. Which is why I was wondering if I could do it between batteries--could be a nice clean install.

Great idea on the winch cutoff.

Thanks for the response.
 
The body ground and engine ground are there for engine, vehicle sensors and other equipment to have a good ground source.
As others have posted.... I would put the disconnect on the positive cable....
On my '93 PZJ75 I have an electrical disconnect for the positive cable mounted near the battery to shut off power to the winch "just in case."
 
In fairness, it's more of a personal preference for me. Either + or - will effectively kill the power. I just have a preference towards the + side being disconnected.
Between the batteries is entirely dependent on how they are routed. If some previous owner did some creative wiring, you could accidentally kill half you voltage instead of all of it. If I were doing it, I would steer clear of splitting the system in any manner. Not that it would, but conceivably you could introduce some resistance that didn't show up immediately between the 2 and create a low amperage situation. While you could do that with the single shutoff on the line out, it would be less likely to create an uneven load across the batteries.
I haven't actually thought about this in quite a long time, so it's an interesting mental exercise.


And, again, agreed on the winch cut off. I have actually had that "just in case" scenario. Burns a hole right through aluminum on a Land Rover body.
 
CharlesHS said:
The body ground and engine ground are there for engine, vehicle sensors and other equipment to have a good ground source.
Click to expand...
I understand having a good ground but would think the ground to the engine block would be adequate. I guess the body ground is just for redundancy.
 
Nas90tdi said:
And, again, agreed on the winch cut off. I have actually had that "just in case" scenario. Burns a hole right through aluminum on a Land Rover body.
Click to expand...
:rolleyes: Land Rover
 
Not really, on the engine ground being sufficient. Drive train is rubber mounted and in a perfect world does not have any direct contact to the chassis. It in fact does, in a round about way. But, you want to provide a good line for the electrons to flow down.
Ground issues can cause a world of annoying,unexplainable, and hard to trace issues. I believe in redundant grounds actually.
One suggestion. I use welding cable for all my cables. It's tough, and very flexible. I have a couple of different crimper's, but my favorite is super simple and effective.
https://www.amazon.com/gp/product/B00E1UUVT0/ref=oh_aui_search_detailpage?ie=UTF8&psc=1

I make all my cables and heat shrink them. I prefer a battery with screw posts so I can use brass ring terminals. Stops the failing battery post clamp issues. And, doesn't create corrosion nearly as bad.

I personally do not like the clamp on type of replacement terminals. The ones with the 2 bolts that just hold the wire between 2 plates. I have seen far to many of those corroded up and causing current flow issues.
 
:rolleyes: Land Rover

I'll sell you one. The Toyota is me trying get out of that stupid hobby. I have owned a minimum of at least one for the last 20 years. At times I have peaked at about 5. Thinking about selling my 110 and giving up.
 
Nas90tdi said:
One suggestion. I use welding cable for all my cables. It's tough, and very flexible. I have a couple of different crimper's, but my favorite is super simple and effective.
https://www.amazon.com/gp/product/B00E1UUVT0/ref=oh_aui_search_detailpage?ie=UTF8&psc=1
I make all my cables and heat shrink them. I prefer a battery with screw posts so I can use brass ring terminals. Stops the failing battery post clamp issues. And, doesn't create corrosion nearly as bad.
I personally do not like the clamp on type of replacement terminals. The ones with the 2 bolts that just hold the wire between 2 plates. I have seen far to many of those corroded up and causing current flow issues.
Click to expand...
Thanks. I went with quality bits from here:
CE Auto Electric Supply – Automotive Electrical Solutions
Going to do just as you recommended (except for batteries with screw posts). Got some mil spec battery terminals and tinned copper ring terminals, amongst other goodies.
IMG_1401.jpg
 
mxtaco48 said:
I am mounting through the firewall with the switch tucked behind the dash out of view.
Click to expand...
Sounds like you haven't mounted it yet. If you have would love to see some pics of how you did it. I've been looking at trying to use something like this:
Moroso Heavy Duty Battery Disconnect Switch – CE Auto Electric Supply
with this:
Moroso Push/Pull Battery Disconnect Mounting Kit – CE Auto Electric Supply
but am worried I'll be in over my head trying to make it work.
 
I'll post up in a couple days. My BJ71 is at the shop having work done to the AC. I have the disconnect already and have the terminal/24" wire coming in. I don't anticipate any issues with install. My batteries are on the left side of the vehicle(RHD), so that was where my logic told me to put it. If someone was sneaky enough to try to jump my truck, at least I was going to make the switch hard to find.
 
@Nas90tdi, in your estimation, any reason I couldn't use a battery disconnect for a dual battery setup to accomplish separate disconnects for both vehicle power and winch with one switch? Circuit #1 would be usual setup--24v from high side battery to switch to starter wire and vehicle harness but also a short jumper wire to the #2 circuit. Output of circuit #2 would go to winch. Circuit #1 on for normal use. Both circuit #1 and #2 on when winching. Circuit #2 never on by itself unless I want to kill my batteries. Seems to make more sense than having two separate disconnects.
m-Series Mini Dual Circuit Plus™ Battery Switch - Black - Blue Sea Systems
 
You could also look into Perko switches for dual batteries used on boats. That might be a better solution for your last comment. I use it when switch from accessories only to starting. Ensures I have enough juice to start up and get home.

PERKO Inc.
 
In answer to that question, I agree with the Perko suggestion if doing that type of set up. I have had them for years on my boats and they seldom fail. You can get them to run various numbers and banks of batteries in one switch.
 
Thanks @mxtaco48 and @Nas90tdi.

Disclaimer: I'm an electrical (amongst other things) idiot.

Looked at all the options for Perko switches and don't think any will work for what I want to accomplish. Most of these are setup for dual battery 12v systems with only one pole for output and two poles for 12v input. I'm sure you know this but I'll say it anyway. I don't have dual 12v systems or even a 24v system with a separate 12v house battery but rather dual batteries in series making a 24v system. If possible, I want a single switch that takes a single 24v input and supplies two separate 24v outputs, one for the starter and wiring harness and one for the winch. The Blue Sea switch I referenced would allow me to do this if I can wire it as I questioned above. I guess it's not that big of a deal to just get two disconnect switches and use one for the truck power and one for the winch power. Was just hoping to accomplish with one switch.

Thanks again
 
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