Electrical help?

So I am by no means an electrician so when it comes to wiring up lights i always have a hell of a time, so this time I decided to come here first! I am going to be adding a fair amount of new LED lights to my Cherokee. I'm using anywhere from 18watt LED to a 300watt LED Bar and several sizes in between mostly 27watt. I have 8 blue LED rocker/toggle switches that I want to use they are the 5 pin dual LED back light style. Here is my wiring diagram i put together can someone who knows what they are doing please take a look and see if there are any issues? Thanks

<a href="http://s1372.photobucket.com/user/millergt1551/media/LEDLIGHTS%20WIRE_zpsdk5nzuwm.png.html" target="_blank"><img src="http://i1372.photobucket.com/albums/ag349/millergt1551/LEDLIGHTS%20WIRE_zpsdk5nzuwm.png" border="0" alt=" photo LEDLIGHTS WIRE_zpsdk5nzuwm.png"/></a>

Also can I run them in a parallel or some kind of circuit to save excess wires?

<a href="http://s1372.photobucket.com/user/millergt1551/media/LEDLIGHTS%20WIRE%20ROCKER_zpsdai81uae.png.html" target="_blank"><img src="http://i1372.photobucket.com/albums/ag349/millergt1551/LEDLIGHTS%20WIRE%20ROCKER_zpsdai81uae.png" border="0" alt=" photo LEDLIGHTS WIRE ROCKER_zpsdai81uae.png"/></a>

I've been lurking on this forum for a long time. I'm a proficient Renix guy. I'm also a master electrician. You're drawings look correct, with a few things I think you shouldn't do.

In the first picture, it looks correct (Not knowing that particular rocker switch, I'll assume you've got the pinout correct). What I don't like seeing is generic numbers for fuse ampacities. Just remember, the whole reason to add fuses is to protect the wire from over-heating, catching on fire, and ruining your Jeep and your day. Size the wire for your light's load, then size the fuse for that size wire. Depending on how many lights your running off your relay, you might need a 30A supplying the load. However, I seriously doubt you'll need wire large enough to fuse at 30A for your control wiring operating the relay. But, you already knew that, right?

In the second picture, daisy chaining your negative conductors for your switches' pilot lights' is OK. You will never have so many in parallel that you would overload those negatives. However, running a common feed to each relay for the lights wouldn't be my preferred way of doing it. But if you are going to, than run the correct size supply conductor to your relays for the sum of ALL your loads, and fuse that wire accordingly. Then, run your individual load conductors off each relay, size accordingly, then fuse for the size of those conductors. Seeing all 30A fuses looks like you're just throwing a fuse in here and there because its the thing to do. But, you knew that too, right?

I'll presume you're just brain storming. But, for the sake of mentioning it rather than risk not knowing, I thought it was worth mentioning.

You don't need a fuse between the relay and the switch #85 and #3.

And yeah do the math for the fuses, LEDs pull very little amperage.

I do use fuses on control circuits. Ever see a vehicle after a fire that started with the wiring? I have. Sources of ignition aren't limited to the large or long conductors only.

Use the fuse there too, unless you're pulling power for the switches from a circuit that is already fused, and the same size as what you would have fused it at.

He has two fuses on the control circuit, there is no need for the one I mentioned....

Ahh yeah I'd get rid of the 85 fuse too. It's already fused before the toggle where it should be.

Basic calculations will give you the amp draw of a given device if you know two of the three variables. 27 watts divided by 12 volts equals 2.25 amps. If you have two 27 watt lights, then the total load is 4.5 amps. I'm not an electrical guy, so I can't tell you what the fuse rating should be. IMO though, I wouldn't put more than a 7 amp fuse on that circuit. The 300 watt light is 25 amps.

As far as daisy chaining the grounds, the only way I would do that is by calculating the entire load of everything in that ground circuit and sizing the wire for that load as AJPulley stated. The ground wire has to carry the same amount of current as the positive cable. If the wire is undersize, it will create excess resistance and heat, possibly leading to a fire. In all honestly, most switches will be rated for at least 5 amps(be sure to check though), so you could run two 27 watt loads without even using a relay(though I would run one anyway). I have also seen switches rated for 20 amp loads. I would absolutely run a 30 amp relay on the 300 watt.

You'll need to google for a DC ampacity chart to find the correct wire size for the circuit length, amp load, and voltage drop. A quick search is only giving me charts for AC. One note on circuit length: It includes the totality of the circuit...it's not just the length of the positive wire or the negative wire. It's both of them put together.

I'd imagine most wires would be fine to run all of the toggle switches, if they draw an amp I'd use different toggles.

Switched ground prevents all the issues of running two hot's... fuse one, split it to both, and switch the ground. It also keeps the backside of your switches non hot.

xcm said:

Switched ground prevents all the issues of running two hot's... fuse one, split it to both, and switch the ground. It also keeps the backside of your switches non hot.

Click to expand...

Humm, thats odd. not many know the way of ground switching. I don't post much about it, cause most shoot it down, as Witchcraft or warlock magic.

I use ground base switching when I can. Its safer.

Some switches you cant use ground based with, the ones with indicator lights. Mainly the ones with LED indicator lights. I've tried, but the LED will glow when its off.


machinisttx, on the grounds for the switches, those can be safely daisy chained. The "LOAD" is not using those grounds. Its only to illuminate the small LED or lamp in the switch when its on. That wire can be smaller, not real small, I'd still use AWG16 or 18. I think on those switches, one ground is to light up when switch in "ON", and the other ground is to light the "logo" on the switch at all times. There is a different switch, where the "logo" is light from the trucks light switch. That is, if the lights are on, then the logo will be on.

Whether you switch ground or power(assuming no relay in the system), you're still running the same amount of current through the switch.