Check my accessory wiring diagram!

[MagicBeans]

It's come time for me to wire up all the accessories I've managed to acquire, and now I'm perplexed by having to wire up so many lights and put them on one switch. So if there are any 12v guru's out there who can review my diagram, it would be greatly appreciated. I've done the calculations and made sure I'm not overloading my bluesea fuse block, and I've got the appropriate gauge wire for everything. I'm trying to keep the wiring as simple as possible, and will not be using lit switches or wiring anything so that it is only on when the ignition is hot. I know this has the potential to result in some dead batteries, but I'm pretty OCD when it comes to things like leaving stuff on. My biggest concern are the relays. I'm not sure they will work they way I have planned. I would like to make it this wiring as clean as possible and avoid using a bus bar or something similar. That's why I've got my four roof rack lights on two relays and one switch, although I don't think I have to because they only draw about 12 amps total (HID's). Any help or advice with this would be greatly appreciated, and I'll post up photos as I get the wiring done.

 

[slcfj62]

Sent you a PM. I have some ideas I can share, depending on how you want to proceed.

 

[MagicBeans]

No, wait... That first diagram won't work, because the relay's have to get power coming off of the switch. And I left out a set of lights. Instead, I could use one fuse to send power to all of the switches (daisy-chain them together) and distribute power from one relay to all four roof rack lights. In other words:

 

[ntsqd]

Relays can be controlled by switching the hot or the ground. Either way works fine.

With several sets of lights it can be helpful to have a Master on/off switch so that you can turn them all off at once.
Some folks like to draw light relay control power from the lighting circuit that those lights will only be used with. For instance you might tap into the low beams for fog light control power. That way the fogs turn off when you go the high beams. Not my preference, but it is one way to do it.

I prefer a breaker instead of a fuse at the battery, but that's just personal preference.

 

[S&S1stCruzer]

Few questions:
What size wires are you using through out?
What size relays you are using?
What you total anticipated amps that you would be drawing if you using all power sources.

Thanks, I'm working on setting up my fuseblock also.

 

[VTCDN]

Gents ..

You first must have a time delay system before any load , Adding may be put on the battery after starting , 12-18 secs is normal ..
Second is , 1 battery system , or split 2 and more..

24 volt , PLEASE , only for airplane plus..

Wire size is selected due to run length and the Max amp at start up HOT.
12 volt power / cig outlets are maxed at 5 amps due to the crappy plugs..

When i get my build , Ill post my brain farts plus..

I posted a magic circle , Ohms law plus, next ill post the wire guide for 12 V systems DC .. I have then 6 to 4800 VAC.. or google them out.

VT..
I'm mobile for 4 days ,, PM and ill get to it.

 

[ntsqd]

I'm going to completely, thoroughly, and totally disagree on needing any sort of time delay device/mechanism. None of the mentioned loads will have a significant in-rush current nor will the alternator have much trouble keeping up unless all loads are turned on all at once immediately after starting. Mentioning this just adds confusion. I suggest that the OP ignore this whole idea.

Start with the current of each load (lights, fridge, etc.) and the wire length (fuse block location to load), including the ground wire length. Add 15%-25% more current for "Factor of Safety." Select the wire size according to the desired voltage drop (I'd use 3%).

If you are going to 'daisy-chain' the lights, check that the relay can handle the total current demand of all of the lights. You may need to daisy-chain two (or more) relays to handle the current. These can either be wired directly in parallel, or be wired such that each relay controls several of the lights.

Now you know what the load will be at the fuse block for each circuit. Add all of the loads together to get the total current demand from the fuse block. That allows sizing of the cable from the battery to the fuse block and of the breaker at the battery.

 

[Cruzerman]

I think you need to lose the two grounds that you have connected to the two top switches. If I read your schmatic correctly, they are just direct shorts to ground.

 

[MagicBeans]

I think you need to lose the two grounds that you have connected to the two top switches. If I read your schmatic correctly, they are just direct shorts to ground.

You're right. My switches don't even have that many plugs on the back of them. Thanks!

 

[MagicBeans]

I'm going to completely, thoroughly, and totally disagree on needing any sort of time delay device/mechanism...

Add 15%-25% more current for "Factor of Safety." Select the wire size according to the desired voltage drop (I'd use 3%)...

If you are going to 'daisy-chain' the lights, check that the relay can handle the total current demand of all of the lights.

I don't think I'll be using a delay device. Not really sure what one of those is anyway. Thanks for your help with the wire gauge stuff, but it's mostly been figured out for me. As for the relays, one should be able to handle the load. My four lights on the roof rack draw 2.9 amps each, or about 12 amps for all four.

Unfortunately, I haven't been able to install any of this stuff or make any replys until today. I've been in WV at a funeral for a relative who died in the mine explosion there. I should get started today.

 

[MagicBeans]

Does anyone have any ideas of how I could cleanly make the connection between all four light 'hot' wires and the relay's one connection? I've circled the connection I'm talking about in the latest diagram:

 

[slcfj62]

Screw terminal block. With all those loads, I'm guessing you have a pretty big alternator?

 

[MagicBeans]

Not really sure how big the alternator is. It is the stock cummins 4bt one. I guess this is adding up to a fairly substantial load.... but it won't be more than 125 amps (b/c that's what the fuse block can handle ) and I have dual batteries and I don't plan on running this stuff all at once. I've been contemplating adding my arb air compressor and air locker actuators to the fuse block too. Am I pushing my luck?

 

[slcfj62]

125 amps off of this one battery. How is the load on the other one? Your alternator could very well be smaller than 125 amps. You probably want to check on that. But, you probably won't be running all those loads at the same time either. So you may not have any worries. It would be a bummer however, if you were on a trail in the dark and reached over to engage your air lockers and the fuse blew.

 

[VTCDN]

No worries ..


VT

 

[MagicBeans]

Wiring is well under way and there have been no major issues so far. Here's a few of my progress:

 

[IrollwithTojo]

Pics of the rest of the truck?

 

[MagicBeans]

Two pics of the final bracket, and one of my 12v outlets in the rear.

 

[MagicBeans]

Now I've hit a snag. I had planned on powering the arb air compressor off of the fuse block... until I discovered the compressor draws 40 amps. The fuse block is only rated at 30 amps per circut, so I've got to go another route. I don't want to tie it directly into the battery because it's so far away I'd have to extend the wire and upgrade its diameter. I'm wondering what would happen if I connected it via ring terminal to the main wire feeding the fuse block? Or could I connect it to the wire feeding my battery isolator (for that battery)? Either one of those solutions would significantly shorten the amount of wire I would need to use to power the compressor, and I could use the in-line fuse included with the compressor.

 

[MagicBeans]

Time to finish this thread. Lights are wired up, and I used them for the first time this past weekend at Spring Tide Ride. Some last pics of the installation. The two empty switch blanks will house my ARB Air Locker switches. Compressor switch is on the other side.