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How to wire multiple accessories?

11K views 6 replies 4 participants last post by  Eric63M  
#1 ·
Hello all.........

I have an 84 Cutlass with a 383 stroker that I've been workin on and am in the final stages. I have a few questions about constant 12volt and switched 12volt sources. I cleaned up the engine bay and do not have the factory wiring underneath. The ignition and starter wires are about all thats there. I have neon lights goin under the car, in the wheel wells, in the trunk, under the dash and under the hood. Also have led running lights in the bumper. Most of that is for the car shows. I know I cant run all of this from the ignition wire. How can I power all of this without causing a fire. Where do fuses and relays come into play? I'm also thinkin of adding an isolator and another battery??

Thanx in advance, Chris.
 
#2 ·
First a couple of questions:
- Do you have a list of what electrical items you want to install, along with an estimate of how many amps they will draw?
- Are you trying to keep the engine bay (or some other area of the car) very clean, with no wiring? Or are you okay with putting a fuse box in the engine bay or up under the dash?
- Do you have an estimate of how much you want to spend on the fuse box and wiring? Some of the nice looking stuff, and some of the sealed boxes for under-hood use are fairly expensive.

Take a look at some of the wiring and fuse boxes from Painless Wiring and see if it might work. There are other companies with similar items, but Painless has a good selection you can see online. Something like this may work for you.
http://www.painlessperformance.com/webcatalog/largeview.php?SearchField=70107&SearchAll=Street Rod

Bruce
 
#4 ·
75gmck25- Im composing a list of everything I want to install today.

302 Z28-Thats what I've been thinkin about and I believe I have one of those in the garage, still in the packaging. With that, I just run a positive lead from the battery and connect the accessories to it? How to determine what size fuses to use for each?
 
#5 ·
labreejr said:
302 Z28-Thats what I've been thinkin about and I believe I have one of those in the garage, still in the packaging. With that, I just run a positive lead from the battery and connect the accessories to it? How to determine what size fuses to use for each?
You will have to determine the load of each device(s) per circuit. The main wire feeding the fuse panel also needs to be sized per the total load based on the total fuse sizes.

Vince
 
#7 ·
So to start you are going to need to calculate the amp usage of the components (should be stated by manufacturer).

Next you are going to need to have the parts installed, you can do this yourself just don't hook up any wiring to anything yet.

Now is where it gets confusing if you know nothing about electrical circuits, and ohms law. You can run the wiring to turn everything on with one switch or different switches, just remember every switch you install is going to be running another circuit.

1 - find a fuse-able link (IE a unused fuse spot in your fuse box, or installing a separate fuse block like the one posted by 302 Z28.), pick a spot for instillation that satisfies your needs.

2 - next you need to figure out the plans for how you want to run your wiring, you can run relays or a switch for the power, i would recommend using a relay for a high amp circuit, pick a relay that will handle the amperage of the circuit. Find a place for the installation of the relay.

3 - next run your wires discretely, and make sure you don't cut them until everything has been guaranteed to fit. leave extra length on the wires for now until you have everything hooked up and buttoned up (wires secured / hidden). at this time you also need to install your switch in location you have chosen.

4 - hook up all of your wires to your components, make sure to do it correct the first time, if you are in doubt check it again and make sure everything looks right. Make sure you use crimping tools and the proper connections, or solder everything. If you go through any type of metal make sure to use grommets.

I've attached a schematic for you, this would be how to wire everything if you only wanted 1 switch for the entire setup. Hopefully this will help you out a bit.

Only use a circuit breaker if you are looking for a solution to restarting without changing fuses (auto reset circuit breakers for example). If you circuit breaker flips there was usually a short somewhere in the system. The auto reset circuit breaker will cut power for a certain amount of time then restart the flow of power. The fuse will break (blow), and cut the power until you replace it and make sure there are not any problems. I would recommend using a fuse.

Hope some of this helps you :thumbup: ,
Eric
 

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