Rear accessories: Dedicated Ground or Chassis?

[midfat]

I am preparing to run a hot shot from the engine bay to the rear cargo area. I'm installing an IBS dual battery system to support a fridge, compressor, modest inverter, etc.. I've settled in 1/0 cable with an 80A fuse at the battery, into a fused panel in the rear cargo area. What's the consensus on running a dedicated ground vs just tapping the chassis? Advantages/disadvantages?

 

[shmabs]

Whenever possible, I like to have a dedicated ground. Trouble shooting for me is easier, because I'm not constantly looking for wherever I might have grounded whatever I installed. The blue sea fuse boxes with dedicated ground spots for every fused circuit are my favorite. Simply by removing two screws I can isolate a circuit and test for shorts to ground, resistance etc.

 

[kevsta]

I just went straight onto the 3rd row seat rail mounting bolt on the rear wheel arch.

 

[Malleus]

The downside of a dedicated ground (I assume you mean the battery) is that there is only so much real estate there. Ideally you would have a "ground" panel near the battery you could tap into, but then your electrical system starts to resemble Victor's lab. IMHO, if you got to that point, you need a standby generator.

For a limited amount of cargo area devices, on a truck with limited or no rust (I have two, don't laugh), I would find a convenient chassis ground:

 

[NLXTACY]

There are plenty of vehicle grounds to use. Not necessary to run a second run of 1/0. That's what I did 8 years ago when I did all of my wiring and in hindsight I'd do it all very differently now.

 

[NLXTACY]

I also, in hindsight, would have stayed consistent with Toyota and made all my switching to ground instead of to power.

 

[LandCruiserPhil]

Its always good idea to run a ground to the frame and more so with dual batteries. If you every loose the main ground to the engine block you only have a #10 to the body ground left providing ground to the system. When you try to start your truck it can only see that #10 body ground or possible from other accessories that had a dedicated ground to the battery (ham/CB). A dedicated ground from accessories power will back feed looking for a better ground to start. Big chance for smoking wires ground wires from the body ground or accessories ground. If you have a large frame ground and loose the main ground all the ground straps come in the effect because the can get a good ground from the frame. Not ideal but a frame ground from the battery will provide a level of safety in you ever loose the main ground also providing a good grounding point.

 

[LFD2037]

Its always good idea to run a ground to the frame and more so with dual batteries. If you every loose the main ground to the engine block you only have a #10 to the body ground left providing ground to the system. When you try to start your truck it can only see that #10 body ground or possible from other accessories that had a dedicated ground to the battery (ham/CB). A dedicated ground from accessories power will back feed looking for a better ground to start. Big chance for smoking wires ground wires from the body ground or accessories ground. If you have a large frame ground and loose the main ground all the ground straps come in the effect because the can get a good ground from the frame. Not ideal but a frame ground from the battery will provide a level of safety in you ever loose the main ground also providing a good grounding point.

Good stuff. Thanks.

 

[kevsta]

I also, in hindsight, would have stayed consistent with Toyota and made all my switching to ground instead of to power.

I thought about this, but didn't like the idea of all these "always live" lines running to all appliances at all times, just waiting for some kind of line fault or accident to happen, so decided I would rather only have power past the switches when I know I've turned it on.

 

[NLXTACY]

I thought about this, but didn't like the idea of all these "always live" lines running to all appliances at all times, just waiting for some kind of line fault or accident to happen, so decided I would rather only have power past the switches when I know I've turned it on.

I suppose you're right. What was Toyota thinking?!

 

[kevsta]

I suppose you're right. What was Toyota thinking?!

you're correct of course, and if they wanted to come round and fit all my stuff for me I'd let them do whatever they wanted

maybe they were thinking its better for fuses to blow when the fault first arrives, rather than having to hit the switch to blow the fuse yourself?

 

[NLXTACY]

you're correct of course, and if they wanted to come round and fit all my stuff for me I'd let them do whatever they wanted

maybe they were thinking its better for fuses to blow when the fault first arrives, rather than having to hit the switch to blow the fuse yourself?

Hence why I said in hindsight I'd follow what Toyota did.

 

[lazy]

Another consideration is wire size. Since you need to take into account "Round trip" wire distance for wire sizing, putting a known ground on the frame or chassis should keep your wire size down.

Of course, much of 'mud is overkill, but there are very things that should need anything more than 4 ga wire on our trucks. For instance, my auto switch for my dual battery setup stipulates that I cannot run anything larger (girth, not awg #) than 6 ga.

 

[midfat]

Great input! My plan as of now will be to run a dedicated ground strap from the aux battery to the frame. This will leave a single 1/0 positive run from the aux battery to the rear cargo area, with an 80A Blue Sea switched breaker at the battery. The hot shot will tie to a 12 gang fused panel in back and I'll ground to chassis. On the advice of @NLXTACY, I'm also installing a six switch panel so I can isolate each of my accessories (leaving 6 spare ports for future expansion), all switching on ground rather than positive.

I tell you, I really wish someone made a tidy power panel for the rear of our 80 Series. Something with a great base to work off of. Something that kept everything clean and professional looking. If only... If only...

 

[NLXTACY]

Great input! My plan as of now will be to run a dedicated ground strap from the aux battery to the frame. This will leave a single 1/0 positive run from the aux battery to the rear cargo area, with an 80A Blue Sea switched breaker at the battery. The hot shot will tie to a 12 gang fused panel in back and I'll ground to chassis. On the advice of @NLXTACY, I'm also installing a six switch panel so I can isolate each of my accessories (leaving 6 spare ports for future expansion), all switching on ground rather than positive.

I tell you, I really wish someone made a tidy power panel for the rear of our 80 Series. Something with a great base to work off of. Something that kept everything clean and professional looking. If only... If only...

I hear it was worked on over the weekend.

 

[lazy]

Great input! My plan as of now will be to run a dedicated ground strap from the aux battery to the frame. This will leave a single 1/0 positive run from the aux battery to the rear cargo area, with an 80A Blue Sea switched breaker at the battery. The hot shot will tie to a 12 gang fused panel in back and I'll ground to chassis. On the advice of @NLXTACY, I'm also installing a six switch panel so I can isolate each of my accessories (leaving 6 spare ports for future expansion), all switching on ground rather than positive.

I tell you, I really wish someone made a tidy power panel for the rear of our 80 Series. Something with a great base to work off of. Something that kept everything clean and professional looking. If only... If only...

Curious, what fuse "panel" are you going with and are the relays with in the box? I'm working on a "panel" for my dual battery so I'm curious what options there are other than the blue sea fuse box which doesn't hold relays and the RTMR and the bigger one that I can't remember the name of....

 

[kevsta]

Great input! My plan as of now will be to run a dedicated ground strap from the aux battery to the frame. This will leave a single 1/0 positive run from the aux battery to the rear cargo area, with an 80A Blue Sea switched breaker at the battery. The hot shot will tie to a 12 gang fused panel in back and I'll ground to chassis. On the advice of @NLXTACY, I'm also installing a six switch panel so I can isolate each of my accessories (leaving 6 spare ports for future expansion), all switching on ground rather than positive.

I tell you, I really wish someone made a tidy power panel for the rear of our 80 Series. Something with a great base to work off of. Something that kept everything clean and professional looking. If only... If only...

sounds a lot like my setup, except for neg switching. not made for the 80, but fits quite nicely

 

[midfat]

sounds a lot like my setup, except for neg switching. not made for the 80, but fits quite nicely

That's almost exactly what I was considering. Blue Sea also makes a nice switch panel that's a bit more compact. I'm not terribly worried about the Voltage meter as I already have a display on the dash as part of the IBS Dual Battery system. Also, I need to add an outlet for the ARB Fridge/Freezer cord.

I was considering something like this...

 

[retrofive]

That's almost exactly what I was considering. Blue Sea also makes a nice switch panel that's a bit more compact. I'm not terribly worried about the Voltage meter as I already have a display on the dash as part of the IBS Dual Battery system. Also, I need to add an outlet for the ARB Fridge/Freezer cord.

I was considering something like this...

Fear not. @NLXTACY is working on something. Plenty of switches to do things.

 

[NLXTACY]

Fear not. @NLXTACY is working on something. Plenty of switches to do things.

Gotta start somewhere