Hope to clean up my embarrassing 12v (1 Viewer)

[JM74]

I realize this has been covered before and i hate to be that guy. I also tried to use the blue sea circuit wizard online tool. But still I can't wrap my head around what amp circuit breaker I need and what size cable I should be using ect... wiring and such is really not my forte

My current setup looks like this.. which is just a mess of previous owners' work and my add ons.

My current plan is a 12 bay blue sea fuse block with a negative bus. Im hoping to mount this either in the driver's footwell or the glove box. I would like to have a circuit breaker near the battery and just have 2 clean lines going from the battery through the firewall to the fuse block in the truck.

I'm not sure what size cable I need to run and what size circuit breaker i need. Im thinking 8-4awg? and an 80 or 120 amp circuit breaker? My current power needs are 2 10" led spot lights on the front bumper, a Ham radio, a CB radio, a 12v socket, a 12v dual USB port. In the future, I want to have maybe a fridge and maybe some more aftermarket lighting.. but who knows. I think I would like half of the stuff on switched power and half constant. From my reading, i will need a relay for switched power but im not sure the schematics of this?

If anyone has some info that would help me out with this that would be amazing as im super green to wiring and 12v work.

Cheers

 

[ppc]

First thing you need to do is address the battery. It is not the correct battery as the posts are reversed. For safety reasons the positive post should be located towards the center of the engine bay to reduce the possibilities of shorting the positive connections to the hood or fender. If your going to cleanup wiring and put in new longer battery cables then you could use your existing battery just rotated 180 degrees.

 

[JM74]

First thing you need to do is address the battery. It is not the correct battery as the posts are reversed. For safety reasons the positive post should be located towards the center of the engine bay to reduce the possibilities of shorting the positive connections to the hood or fender. If your going to cleanup wiring and put in new longer battery cables then you could use your existing battery just rotated 180 degrees.

Aha I knew this was wrong, I remember when i first got this 80 i was like hmm something seems off with this battery area. There's the answer. Id be open to replacing it, this is just a cheap Kirkland/costco battery that is probably 6-8 years old.

Any suggestions? I know i used a group 31 in my last 80 and i had to trim the tray to fit it, would like to avoid that this time..

 

[gummycarbs]

What is the total wattage of the accessories you're planning?

Take the total watts, divide by 12, and that's how many amps. Multiply by 1.25 to get the approximate circuit breaker rating (you're probably fine just rounding up to the next circuit breaker size). Look at the Blue Seas ampacity chart for the wire gauge.

 

[ppc]

Personal opinion is the group 31 is too large of battery dimensionally to fit in the box. It would require the box be cut up the current exit holes would be to low to run cables. The correct battery would be a group 27F.

Also the protective grommets are missing in the box. Replace those or use rubber hose/tubing split down the middle to make your own. Without the ruff edges of the box can damage any wiring.

 

[JM74]

What is the total wattage of the accessories you're planning?

Take the total watts, divide by 12, and that's how many amps. Multiply by 1.25 to get the approximate circuit breaker rating (you're probably fine just rounding up to the next circuit breaker size). Look at the Blue Seas ampacity chart for the wire gauge.

Im not sure the current draw, It just a ham radio, cb radio, set of cheaper LED lights and a 12 v socket thats currently hooked up. I'm hoping to eventually have a fridge and a few other things hooked up though. So maybe around 300w or so?

 

[JM74]

Personal opinion is the group 31 is too large of battery dimensionally to fit in the box. It would require the box be cut up the current exit holes would be to low to run cables. The correct battery would be a group 27F.

Also the protective grommets are missing in the box. Replace those or use rubber hose/tubing split down the middle to make your own. Without the ruff edges of the box can damage any wiring.

Awesome tip, appreciate that Phil

 

[Broski]

Personal opinion is the group 31 is too large of battery dimensionally to fit in the box. It would require the box be cut up the current exit holes would be to low to run cables. The correct battery would be a group 27F.

Also the protective grommets are missing in the box. Replace those or use rubber hose/tubing split down the middle to make your own. Without the ruff edges of the box can damage any wiring.

The Group 31 battery fits fine with a little trim to the inside corner of the battery box. And I mean a little.
The holes fore the cables are fine.
I prefer to run the group 31 Odyssey instead of a dual battery system for the simplicity and weight shavings.

 

[Rusty Marlin]

Im not sure the current draw, It just a ham radio, cb radio, set of cheaper LED lights and a 12 v socket thats currently hooked up. I'm hoping to eventually have a fridge and a few other things hooked up though. So maybe around 300w or so?

set up a table with the device name, and power requirements. The instructions on all those products will have that listed.
Power = watts=Voltage X Amps.
If you're given two, you have the third and you always have the Voltage, its 12.
Let excel do the work for you. Add up the total amperage at the end. This will tell you the size of the breaker to put in ahead of the panel as a main.

Draw	watts	Volts	amps
Blue Sea 12v w/ 4x USB		12	15
ham radio	50	12	~4
Big A$$ LED light bar	500	12	~42

61 amps.
lets say your fuse box is on the fire wall, like mine. so round trip for hot and ground is 10 Ft (assuming you wire all your grounds back to the fuse box... I don't, I terminate to vehicle grounds at closest location, but this is for an example....

You need to do some home work and plan the circuits before you just start buying stuff.
Its not difficult, the math is dirt simple and there's all manner of good safety info to keep you from burning your rig to the axels.
But you have to the the home work first.

 

[JM74]

The Group 31 battery fits fine with a little trim to the inside corner of the battery box. And I mean a little.
The holes fore the cables are fine.
I prefer to run the group 31 Odyssey instead of a dual battery system for the simplicity and weight shavings.

Yes agreed, I ran a group 31 in my last truck with a minor trim to the box. Considering it again for this truck as it is usually cheaper to get a higher CCA battery in a group 31 than the proper size battery, at least that was my experience last time I bought a battery. Appreciate it!

 

[JM74]

set up a table with the device name, and power requirements. The instructions on all those products will have that listed.
Power = watts=Voltage X Amps.
If you're given two, you have the third and you always have the Voltage, its 12.
Let excel do the work for you. Add up the total amperage at the end. This will tell you the size of the breaker to put in ahead of the panel as a main.

Draw	watts	Volts	amps
Blue Sea 12v w/ 4x USB		12	15
ham radio	50	12	~4
Big A$$ LED light bar	500	12	~42

61 amps.
lets say your fuse box is on the fire wall, like mine. so round trip for hot and ground is 10 Ft (assuming you wire all your grounds back to the fuse box... I don't, I terminate to vehicle grounds at closest location, but this is for an example....
View attachment 2796198

You need to do some home work and plan the circuits before you just start buying stuff.
Its not difficult, the math is dirt simple and there's all manner of good safety info to keep you from burning your rig to the axels.
But you have to the the home work first.

Great info! appreciate the knowledge, looks like I have a chart to make and some research to do to see what all my accessories' wattage is!

Wondering if you have any knowledge on how I would go about having half of the switch pannel on keyed power? from my understanding, this needs a relay? but what would that schematic look like?

 

[Rusty Marlin]

replace all the verbiage on pin 87 with "input to fuse block"
Then you need to jumper all the 12v+ that you want to fire on that relay together.

https://www.bluesea.com/products/9216/Terminal_Block_Jumper_for_65A_Terminal_Blocks

 

[Rusty Marlin]

I fab'd up a relay holder that is attached to the firewall by my hood hinge mounting bolts.
This way its right next to the fuse block.

Yellow tape is for Amber Fog lights, red for ditch lights. Just a visual so that when I wired them up I kept the wiring straight.
They also correspond to the position in the rig. Amber lights are closer to center line, and so is the relay and the wire in fuse block and the switch in the cab.

Gotta have a plan.

 

[JM74]

I fab'd up a relay holder that is attached to the firewall by my hood hinge mounting bolts.
This way its right next to the fuse block.

Yellow tape is for Amber Fog lights, red for ditch lights. Just a visual so that when I wired them up I kept the wiring straight.
They also correspond to the position in the rig. Amber lights are closer to center line, and so is the relay and the wire in fuse block and the switch in the cab.

Gotta have a plan.

Looks clean! appreciate the tips / inspiration!

I think my homework is nearly done, figured out what gauge i need to run to the fuse block and 100amp breaker seems like it will be plenty. Just trying to wrap my head around how the relay works, watching some youtube videos now.

Thanks rusty!

 

[Rusty Marlin]

Here is how I used a couple relays in my rig for powering features on the 7 pin trailer plug.
The top relay is triggered by the reverse lights on the truck and fires up the reverse lights on the trailer.
The bottom relay is triggered by my running lights and allows the "house" battery in the trailer to be charged while driving. The battery can only charge when the lights are on, so there's no chance of it draining my rigs "start" battery dry.

In the above image the thin white wire is ground for the relay. The thin black wires that go to the POSI-TAPS are the signal wires for the relays.
The #10 wires (green and Black) are the pass through power. Both relays are rated to 60 amps.
I used 10/3 tinned marine wire because someday I'll tie into that and put some serious reverse lights on the rig.
Up front: here is a shot of my fuse box with the cover off and some of the wire harness moved around so you can see the jumpers.

1,2&6 are jumpered and fed by a stranded #10.
#1 Out goes to my 12V and USB charging station

#2 Out goes to my LED under hood work lights.
and #6 Out goes to the trailer reverse lights. that are activated by the relay shown in pic 1 above. They are adequate and only pull something like 3 amps, hence the 5 amp fuse.

#3 IN is jumpered to #4. These run the power to the fog and ditch lights through the relays mounted on the bracket next to the fuse box.

The trailer brakes are fed off a 40amp circuit breaker right at the battery (blue tape).
The house battery on the trailer is fed from a 30amp breaker also right at the battery, (plain black)
They are both mounted to a custom bracket a fab'd up and its attached to the charcoal canister bracket.

One more thing, radios...HAM and CB... should be run as independent hot and ground to and from the battery directly, not run through a fuse box to minimize noise in the power feed. So even if you run a central fuse box with a single main, you'll still have a min of three surplus wires hooked to the positive pole of the battery.

I hope this helps you.

 

[LandLocked93]

I just want to say that the AC extension cord, while intriguing, is making my eye twitch.
Sure hope it's not being used to power anything in the truck.

 

[LandLocked93]

dup

 

[BILT4ME]

I just want to say that the AC extension cord, while intriguing, is making my eye twitch.
Sure hope it's not being used to power anything in the truck.

If you're referring to the orange extension cord on the OP's post ( @JM74 ) I'm guessing that's a block heater with circulation pump based on the additional wye in the coolant line as well as his location.

Gotta keep it warm enough to start in the cold temps.

 

[JM74]

If you're referring to the orange extension cord on the OP's post ( @JM74 ) I'm guessing that's a block heater with circulation pump based on the additional wye in the coolant line as well as his location.

Gotta keep it warm enough to start in the cold temps.

I just want to say that the AC extension cord, while intriguing, is making my eye twitch.
Sure hope it's not being used to power anything in the truck.

Your good @BILT4ME, spot-on. Yes for my Zerostat circulating coolant heater. Keeps her toasty warm and instant heat in the morning so long as you can plug it in overnight!!

 

[JM74]

Here is how I used a couple relays in my rig for powering features on the 7 pin trailer plug.
The top relay is triggered by the reverse lights on the truck and fires up the reverse lights on the trailer.
The bottom relay is triggered by my running lights and allows the "house" battery in the trailer to be charged while driving. The battery can only charge when the lights are on, so there's no chance of it draining my rigs "start" battery dry.

In the above image the thin white wire is ground for the relay. The thin black wires that go to the POSI-TAPS are the signal wires for the relays.
The #10 wires (green and Black) are the pass through power. Both relays are rated to 60 amps.
I used 10/3 tinned marine wire because someday I'll tie into that and put some serious reverse lights on the rig.
Up front: here is a shot of my fuse box with the cover off and some of the wire harness moved around so you can see the jumpers.

1,2&6 are jumpered and fed by a stranded #10.
#1 Out goes to my 12V and USB charging station

#2 Out goes to my LED under hood work lights.
and #6 Out goes to the trailer reverse lights. that are activated by the relay shown in pic 1 above. They are adequate and only pull something like 3 amps, hence the 5 amp fuse.

#3 IN is jumpered to #4. These run the power to the fog and ditch lights through the relays mounted on the bracket next to the fuse box.

The trailer brakes are fed off a 40amp circuit breaker right at the battery (blue tape).
The house battery on the trailer is fed from a 30amp breaker also right at the battery, (plain black)
They are both mounted to a custom bracket a fab'd up and its attached to the charcoal canister bracket.

One more thing, radios...HAM and CB... should be run as independent hot and ground to and from the battery directly, not run through a fuse box to minimize noise in the power feed. So even if you run a central fuse box with a single main, you'll still have a min of three surplus wires hooked to the positive pole of the battery.

I hope this helps you.

Awesome info thanks rusty. I have heard that about radios that its best to have them directly connected to the battery. I still have in-line fuses on them currently.

So I will have to somehow wire a relay to be trigged by key power and then the relay will allow for half the fuse panel to be powered. I think im just about ready to order some stuff, have this all planned out to about 95%