Need some basic guidance guys.

I have never done any type of electrical work and I am getting ready to wire up some off-road lights to a light bar and also considering some interior/exterior lighting.

I do believe I have read where I can tap into the fuse boxes for my power source. If I can use my fuse box for all the above mentioned installs, how do I know what fuses to use, or how do I use them. All of my lights will run through switches that will be installed in the cab.

A quick electrical class would be highly appreciated.

Thanks!

 

If your thinking of adding a few extras I think you would be better off going direct to the trucks battery and leaving the fuse box alone. Just add inline fuses to each item you add. Use #10 or #12 wire for all your runs and size the fuses for what the items draw, no more.

It would take a lot more text to help you more.. Get some help.. It's better to get help then burn your truck to the ground..

Good luck...

 

I agree with Radio man...I'd go and grap power directly from the battery for off road lights. BUT for the switch power...that id grab inside.....also PLEASE use relays and dont run the full current through yuor switches....thats how fires start.

 

I agree 100%. A nice little Bosch relay won't cost much, and will prevent switch failure, fire, melting truck...etc....

 

Based on the title of this thread, you should probably be telling him how to hook up a Bosch-style relay \


-30 = 12V+
-85 = Constant Ground
-86 = Your vehicles ACC circuit (ignition)
-87 = The item you want to turn on
-87a = Leave it alone

 

To piggyback on this thread, if I were wanting to run unswitched constant power off the battery to an additional 12V port at back of my bed and also LED bed lights that turn on/off with a switch would an inline fuse be sufficient or is a relay needed in this application. I understand the fuse but don't have experience on relays and what they do and why needed.

Please educate me as well. Thanks

 

For the 12V port is completely depends on if you want to be able to get power to that port without the key being on. If you want it on all the time, you don't need a relay. If you don't, you need to use a relay as I described above.

For the LED bed lights it could go either way. If you "forget" to turn off your switch without a relay you could drain you battery. However, WITH the relay you would have to have your key "on" to be able to use them

 

Sounds like I will NOT use a relay then as I want to be able to plug something into the 12V port and also be able to turn on the bed lights without the key in the ignition. I want constant power to them even if truck is off in case I'm getting into my covered bed at night without truck keys in ignition.

Since I'll be using just an inline fuse then for these two additions (bed lights & 12V truck bed port) what size inline fuse would be appropriate for this installation?

Thanks again for the info and knowledge.

 

A relay is basically an electrically controlled switch. It contains a coil that when energized will control a set or 2 sets of contacts said to be either "normally open" and " normally closed". The diagram with corresponding numbers ie. 30, 87, 87a, 85, and 86 on the relay show it's operation. 85 and 86 being the coils power and how you are going to control the contacts. Normally open contacts will become closed when the coil energizes and normally closed will become open. For controlling lights you will want to use a normally open set of contacts which is where you will run your constant power from the battery to terminal 30 on the relay which is the common point and from 87 you will run out to the lights you want to control ( assuming 87 is normally open, not closed....see purchased relay for verification it will show it). Power the coil with switched power so it energizes when the truck is on( or power it how ever you want it powered, constant if you want to turn them on without the truck on, switched power is like a fail safe so you can't leave them on) this power and ground will goto terminals 85 and 86 to power the coil. If you want two things controlled by the same relay use a 2 pole single throw relay. Run a 40A relay and you will be fine. Always use fuses to protect the wiring regardless of constant power or switched. Size the wire based of the power of the load you are running. Use the formula ; power (watts) \ voltage (v)= current (A) this will tell you what size wire you need. #14 is good for 15A, #12 is good for 20A , #10 is good for 30A. Size your fuses accordingly. 15A wire gets a 15A fuse. Hope this was helpful. Could elaborate more if needed let me know and I'll post a quick wiring diagram for one if needed. Good luck

 

In regards to sizing fuses, you always size your fuse to the size of the wire. You want the size of the fuse to be lower than the wire's rating. (see the chart below)

So, you really want to choose your size of wire based on how many amps your 12v outlet and LED lights pull. (should show on the package)

http://www.engineeringtoolbox.com/am...uge-d_730.html