wiring multiple 12v plugs

A

aeo

Well-known member
Let me preface this with I'm new to electrical work, as well as the rest of the things I attempt on the truck.

I want to wire in a few 12v/usb plugs in one area. I have 3 plugs and they each have a fused + and a separate - wire. I'd like to just have 1 + and 1 - wire to connect to the fuse panel. How do I streamline the wiring on the back of the outlets?

Thanks,
Alex
 
The_Vermonster

The_Vermonster

Well-known member
You want to avoid daisy-chaining the outlets. That will be wiring the sockets in series, which means you will experience voltage drop. Basically the first outlet takes the power it needs and lets the excess pass to the next outlet. As you go down the wire, you will have access to less and less voltage. The only safe way to do this is to have a single positive power 2 USB, as they are generally limited to 5v. That gives more than enough spare power for two full power devices.

The right way would be to run a larger wire then have it split to the smaller wires going to each outlet. That keeps the outlets in parallel.

This is a decent write up about circuits http://www.pirate4x4.com/tech/billavista/Wiring/Part1/ Scroll down about half way to the Practical Circuits section.
 
A

aeo

Well-known member
Thanks for the link, that is a nice and concise write up.

Now, I obviously need to do this in parallel and not series. Is my best bet to put an aux fuse block near the outlets and then I just have my two wires to the main fuse box, or should I go with a distribution block? I'd like them to be switched.

Thanks,
Alex
 
R

rlynch356

Well-known member
I would use a relay for switched power and run that to a fuse block then to the outlets.
The switched pwr wires in the truck are pretty small 16g or so and if used for anything other than triggering a relay can quickly get over whelmed (been there)
I just installed a 12gang blue sea fur box in the battery compartment (all hot) and use a positive stud mount for the lights all have relays.
For 3 12v sources I would try to out on a 10-12g main wire.
 
The Dro

The Dro

Illustrious
The_Vermonster said:
You want to avoid daisy-chaining the outlets. That will be wiring the sockets in series, which means you will experience voltage drop. Basically the first outlet takes the power it needs and lets the excess pass to the next outlet. As you go down the wire, you will have access to less and less voltage. The only safe way to do this is to have a single positive power 2 USB, as they are generally limited to 5v. That gives more than enough spare power for two full power devices.

The right way would be to run a larger wire then have it split to the smaller wires going to each outlet. That keeps the outlets in parallel.

This is a decent write up about circuits http://www.pirate4x4.com/tech/billavista/Wiring/Part1/ Scroll down about half way to the Practical Circuits section.
Click to expand...
What he said...
 
The_Vermonster

The_Vermonster

Well-known member
aeo said:
Is my best bet to put an aux fuse block near the outlets and then I just have my two wires to the main fuse box, or should I go with a distribution block? I'd like them to be switched.
Click to expand...

Yeah a fuse block would be the safest.

This would be a minimal setup https://www.amazon.com/Blue-Systems-Blade-Fuse-Blocks/dp/B01BV1MS1K?th=1

This is a bit better. It gives a negative busbar too. https://www.amazon.com/Blue-Systems-Blade-Fuse-Blocks/dp/B000THQ0CQ?th=1

You should put individual switches near the outlet unless you want to be able to turn all the outlets on and off.
 
Uncle Douglas

Uncle Douglas

Well-known member
Callsign: delete
aeo said:
Doesn't that have the sockets wired in series? Is there any noticeable loss in voltage?
Click to expand...

The only thing that might be wired in series would be the USB and 12v socket.
The switches are supplied with pig tails but are to be wired directly.
Since the USB drops voltage down to 5v I doubt seriously there is much drop @ the 12v outlet. The max load you are supposed to put on one of the lighter type sockets is 15a so again not a concern. For my purposes I have everything in the overhead electronics box powered through a single magnetic/hydraulic circuit breaker on my main panel. I have a buss bars for power and ground in the overhead powered by that breaker. In the event of an issue I can kill everything but the bilge pump, nav lights, and engine by throwing a single breaker.
 
A

aeo

Well-known member
I went digging around and found that I have lots of space for more fuses. As in almost half a panel at the tunnel. But those don't have any power. I tested those with a multimeter.

Under the seat box I have an aux panel and I don't think all of it is really being used.

For my needs (2 separate 12v and 1 dual usb) could I wire those directly to an unused fuse? Like the 60 a that I assume is the central locks. It has the key icon.

I think the others are in use, I haven't looked below the box to find out but I have those features in my truck- glow plugs, AC, and seat heat.
 

Attachments

  • IMG_0558.JPG
    IMG_0558.JPG
    120.9 KB · Views: 195
  • IMG_0560.JPG
    IMG_0560.JPG
    116.2 KB · Views: 200
rocky

rocky

NAS-ROW Addict
I'm a big fan of keeping the truck's systems separated from any user installed systems. Consider adding a secondary for accessory only panel.
 
chris snell

chris snell

Administrator
Callsign: NW5W
Staff member
I would wire an auxiliary fuse block (Blue Sea Systems are my favorite) straight off the battery and hang your outlets off of that. Don't touch factory panels if you can avoid it. I have only one modification to my factory panel and that is to add an extra fused line to get an ignition-hot trigger line to my second aux panel that is used for my 12V fuel pump.
 
A

aeo

Well-known member
chris snell said:
I would wire an auxiliary fuse block (Blue Sea Systems are my favorite) straight off the battery and hang your outlets off of that. Don't touch factory panels if you can avoid it. I have only one modification to my factory panel and that is to add an extra fused line to get an ignition-hot trigger line to my second aux panel that is used for my 12V fuel pump.
Click to expand...

I ordered the Blue Sea one above. I'm going to stick with that plan. I like your battery box set up.

I want the entire fuse block to be ignition hot. How do I do that? Do I need a relay? I plan to add my 12v fuel pump and all aux outlets to the block.

Thanks,
Alex
 
A

aeo

Well-known member
I've been reading and ordering. So far this is what I have: Blue Sea Fuse block, fuse holder, 16 gauge red/black wire for accessory plugs, wire for battery to fuse block.

I am concerned that my fuse holder isn't the correct one. It has a 30A fuse in it. I was planning to install that between the + on the battery and the + on the Blue Sea.

Negative seems obvious- battery to fuse block.

Now, how do I set it up for the entire bock to be ignition hot? As in can someone post a photo or an explanation written for an idiot? I'm planning to put it in the right side locker with the other fuse blocks, seat heat relays, and webasto wiring.

The block is for my accessory plugs and my sedimenter fuel pump. I'll probably end up with 3-6 total accessory plugs for my insulin pump, meters, kindles, and fans for the kids.

Thanks,
Alex
 

Attachments

  • IMG_0631.JPG
    IMG_0631.JPG
    105.1 KB · Views: 182
  • IMG_0632.JPG
    IMG_0632.JPG
    98.3 KB · Views: 192
G

ghoregon

Active member
Very interested in understanding this as well, including the inline fuse between the battery and the block. I have this one for my setup, perhaps overkill:

Blue Sea Systems MEGA/AMG Safety Fuse Block https://www.amazon.com/dp/B004ZJ0WEQ/ref=cm_sw_r_cp_taa_EQ4kzb836FRVT

Along with this fuse:

Fuse - Mega 32V, 125A, 1 pc card https://www.amazon.com/dp/B001FXGLE0/ref=cm_sw_r_cp_taa_eU4kzbYRRMNR4

4 AWG between battery & fuse and fuse & block:

TEMCo WC0189 - 20' (10' Blk, 10' Red) 4 Gauge AWG Welding Lead & Car Battery Cable Copper Wire BLACK + RED | MADE IN USA https://www.amazon.com/dp/B00LIB7WLA/ref=cm_sw_r_cp_taa_nZ4kzb8W32EK8
 
Jeff B

Jeff B

Well-known member
aeo said:
Now, how do I set it up for the entire bock to be ignition hot? As in can someone post a photo or an explanation written for an idiot? I'm planning to put it in the right side locker with the other fuse blocks, seat heat relays, and webasto wiring.
Click to expand...

Alex, I'm glad to see you asking this because I've been meaning to get back to this project.
I ,too, want to add an ignition hot Blue Sea fuse panel.

And I need it spelled out slowly... drawn on a napkin... maybe a couple of pictures thrown in for good measure so I dont spark something up...

dagone



.
 
chris snell

chris snell

Administrator
Callsign: NW5W
Staff member
I'll type it up tonight for you. In short, you find an ignition-hot circuit on the truck's fuse panel and jump that to an unused socket on your fuse panel, where you put another fuse and run that to a relay. The relay acts as a switch to deliver power from the battery to your new ignition-hot panel when it senses current on the line you ran from the truck's panel.

The key to a good install is how you do the wiring. I will post up on that later.
 
Uncle Douglas

Uncle Douglas

Well-known member
Callsign: delete
fwiw. I'm a fan of leaving the dual USB's (minute draw-ie can't kill your battery with them) I install live all the time. I'm the guy that always has the dead iphone and prefer not to have the key on to have the phone charge.

We all use these trucks differently so there is no right or wrong, just whats right for you.
 
chris snell

chris snell

Administrator
Callsign: NW5W
Staff member
Totally agree with Doug. All of my 12V ports are always hot. I use them for phone charging, for my Bluetooth speaker, and for the Engel fridge--things that I want to work all the time.

The only thing I currently use my ignition-hot circuit for is the 12V fuel pump.
 
You must log in or register to reply here.
Top