Electric wiring help!

[carpsniperg2]

Hey guys, I am sure there are a few guys on here that know way more then me. Since I know next to nothing about it Did a few back in high school but that was about it. I have never had problems with running spot lights from my dc plug in's on my trucks. Now they have been giving me fits. Yes I have burnt more then a couple fuses in my day but that is not the problem now. I am trying to wire up a direct power line to my battery so this is what I have come up with. I need to know a few things.

1: is there anyway that this could cook the wires in my truck? I would not think so just running it strait from the battery like this but I want to make sure I don't cook my truck.

2: I put a inline fuse in the line to keep from burning my high dollar spotlights up. Most of my fuses for the dc power in all my rigs are 20watt fuses. That is what I bought and I am guessing that should go before my spotlights. What are you thoughts on this.

3: This is the main one. Do I need to hook up the ground wire to the frame of my truck?

Any help would be great from people who know what's what. I am getting tired of stopping to try to figure out problems when I should be hunting!

Thanks in advance!!!

[lokidog]

Looks pretty similar to what I have rigged for my spotlight on my boat.  You should be able to hook the black line directly to your negative battery terminal without any issues.

Make sure your wire gauge will support the amps.  I like to go one thickness more for the supply line, especially if it is very long, than what the light uses but am not sure that is necessary with DC.  I am definitely not a wiring expert, just look at my boat trailers....   

[Ridgeratt]

Hey guys, I am sure there are a few guys on here that know way more then me. Since I know next to nothing about it  Did a few back in high school but that was about it. I have never had problems with running spot lights from my dc plug in's on my trucks. Now they have been giving me fits. Yes I have burnt more then a couple fuses in my day but that is not the problem now. I am trying to wire up a direct power line to my battery so this is what I have come up with. I need to know a few things.

1: is there anyway that this could cook the wires in my truck? I would not think so just running it strait from the battery like this but I want to make sure I don't cook my truck.

That will only effect the load on the wire in that set up

2: I put a inline fuse in the line to keep from burning my high dollar spotlights up. Most of my fuses for the dc power in all my rigs are 20watt fuses. That is what I bought and I am guessing that should go before my spotlights. What are you thoughts on this.

I would put the fuse as close to the source as you can get it. What was the fuse supplied with the lights? Stick with it.

If you are using a fuse that you have just remember "Bigger is not always Better"

Is the Black object in the photo the switch ?If so the black side goes to the load side which are the lights.

3: This is the main one. Do I need to hook up the ground wire to the frame of my truck?

The entire frame of the vehicle is a ground plane unless it has rubber isolaters to something mounted so the frame is good. Some lights just use a mounting hardware to get a ground.

Any help would be great from people who know what's what. I am getting tired of stopping to try to figure out problems when I should be hunting!

Good Luck

[bearpaw]

   good advice, if this is wired direct to the battery then it should not affect any other wiring on the vehicle, I would keep your fuse as close to the battery as possible. 


You can burn down a vehicle by having a short in the wiring with no fuse to blow between the point of the short and the power source. Wires can get so hot they melt and ignite the plastic coating if there is no fuse.

[SilkOnTheDrySide]

You don't really need a ground wire IMO.  The negative terminal acts like the ground.

[Russ McDonald]

Is that a Cigarette style plug?  Here is what I have learned...wire the red directly to the battery, wire your ground directly to the battery, if you can't wire the ground to the battery there are usually ground points usually in the kick panels of most vehicle.  Like everyone has said so far put the fuse closest to the battery.  You should use the fuse that is recommended by the light manufacture.  I take it you will be plugging the light in when using and then unplugging when not in use?  I ask because if you have any power on the circuit your installing you will drain you battery if your vehicle sits for any amount of time.  Wiring directly to the battery doesn't give you the ability to shut in off.  If you have any questions feel free to DM me.  I have been doing  two-way radio install, full cop and fire vehicle build ups for 25 years.  So I guess I would have some experience in the field.  Good luck.

[bloodhound]

1. as long as its fuzed and the fuse isnt to big you wont cook your truck

2. figure out how many amps the light is supposed to use and put in a fuze thats one size bigger.

3.your ground should be as short as possible! a lot of people dont that. but any time your wiring somthing, you power wire can be as long as you want but your ground needs to be as short as possible. so figure out where you want to mount it then run your wires, cut on anything you dont need, less it has to travel through the wire the better. the frame, body, and anything attached will be grounded. so just find a bolt or nut that is holding anything to the fire wall, the floor, and so forth and attach your ground.

[SilkOnTheDrySide]

1. as long as its fuzed and the fuse isnt to big you wont cook your truck

2. figure out how many amps the light is supposed to use and put in a fuze thats one size bigger.

3.your ground should be as short as possible! a lot of people dont that. but any time your wiring somthing, you power wire can be as long as you want but your ground needs to be as short as possible. so figure out where you want to mount it then run your wires, cut on anything you dont need, less it has to travel through the wire the better. the frame, body, and anything attached will be grounded. so just find a bolt or nut that is holding anything to the fire wall, the floor, and so forth and attach your ground.

What's your reasoning for number three? Because your logic is flawed.

[Heredoggydoggy]

I put an auxilliary plug into my vehicle for a second place to hook a light, and just spliced into the existing lighter circuit.  (my vehicle was made back when cars had ash trays and cigarette lighters)  The circuit is fused at the main fuse panel, and has handled the draw from 2 lights, so it works.  A circuit that was designed to heat a cigarette lighter red hot shouldn't mind a couple of light bulbs!   

[carpsniperg2]

The black thing in the picture is the dc socket/female plug in.

The ground wire supplied with this kit is only like a foot long. Way to short to hook to the battery, unless I add like 5 feet of wire to it and it sounds like I don't want to do that.

I will start with a small fuse. If it cooks it I will jump it up until I get the right fuse to run the light. I screwed up when I was young and learned my lesson on never going to big on a fuse.

The hookup will only be wired in when I am using it. I will disconnect it after use because I know even with the truck off it will still be pulling some juice.

Hope this helps a little more and thanks for helping guys.

[mathewsbow4elk]

Just a word of caution when using spotlights in your rig, don't forget to unplug them when you are done for the day. One of my coworkers inadvertently turned his on as he was exiting his truck for the night, but didn't notice as it was face down. and his new truck burned to the ground in the driveway! Just food for thought!

[WDFW Hates ME!!!]

Carp you can connect straight to the battery, but you have spare fusses in your fuse box. The fuse is your protection, i would wire it to the spare fuse in your box. Also what wattage light are you running? That would help in determining what size fuse and wire to use...

[Russ McDonald]

When did spot light on police vehicles we normally used a 30 amp fuse.  You can ground to anything that is metal under the dash.  There are some grounding points in the kick panels.  What wattage is the light?

[carpsniperg2]

The bulb is 75 watt and its a lightforce 240 blitz.

I don't want to even touch the wires or fuse box in my truck. It makes me nervouse and that is why I am doing it this way.

So it sounds like just ground it to the frame or something metal and it should be good to go.

I have been running lights since I was 7 with my dad. I know a spotlight never ever points down in any of our rigs. Even if its not on, if its been run and got hot you can melt the seats!

[Russ McDonald]

The bulb is 75 watt and its a lightforce 240 blitz.

I don't want to even touch the wires or fuse box in my truck. It makes me nervouse and that is why I am doing it this way.

So it sounds like just ground it to the frame or something metal and it should be good to go.

I have been running lights since I was 7 with my dad. I know a spotlight never ever points down in any of our rigs. Even if its not on, if its been run and got hot you can melt the seats!

I think that a 20 amp fuse would work for you fine and yes ground it to something metal and red straight to the battery.  You should be good to go.

[carpsniperg2]

Alright thanks. I have some 25's and 30's as well if the 20 won't run the light.

Thanks for the help everyone. If anything else has anything to add please feel free.

[Ridgeratt]

Well if your running a 75 watt lamp it should draw some where around 6.25 amps.
So you could get by with a 10 amp fuse. I would run # 14 wire if I was doing it.

 

[carpsniperg2]

I think the wires are either 12 or 14g. Are the fuses rated in watts or amps?

[Ridgeratt]

fuses are in amps. If the wire is 12 you are golden for size! 

[christopheri]

Well if your running a 75 watt lamp it should draw some where around 6.25 amps.
So you could get by with a 10 amp fuse. I would run # 14 wire if I was doing it.

 

This is true. You divide 75 by 12 to get your amps... #14 wire is plenty big enough to handle the load.

[carpsniperg2]

Thanks guys! I always thought there were rated in watts for some reason. So the 20 should be more then enough. Should I maybe drop down to 15? or will 20 pop before I damage the wire or light?

[Ridgeratt]

Thanks guys! I always thought there were rated in watts for some reason. So the 20 should be more then enough. Should I maybe drop down to 15? or will 20 pop before I damage the wire or light?

If it draws 6.25 amps a 10 amp fuse will put you  30% over.

[carpsniperg2]

O.k I will get some lighter fuses then.

[Ridgeratt]

Hey it's your truck!!! 

Bigger is not always Better! Despite what you have been told!

[carpsniperg2]

  That's why I asking the experts Rather pop a couple extra fuses then toast my 200.00 lights

[Ridgeratt]

Far from an Expert. Maybe I should retract my statement's.

What I know about electricity is if you get to close it Hurts!!!

I have referances on both statement's,

[carpsniperg2]

It all sounds right by what others are saying as well. So I think you are onto something for sure. Lighter is always better with fuses. I learned that a long time ago. I know my trucks all have 20 amp fuses rigged for the factory dc plug in's. So I guess that was my thinking behind the 20 amps.

[Ridgeratt]

Just don't forget your safety glasses and welding hood when ya use it the first time. 

[carpsniperg2]

 

[Fishmasterdan]

Just a small note to remember. A resistive load will increase in amps as wire length increases.
Example;
A spot light is a resistive load (unless its LED). If you run 30' of wire your voltage drop will be 6% at 7amps and increasing your amps equally by 6%. Your light will be dim if you use light gauge wire.
This is very important to remember if using 12 volts and run 30' of wire or more.

Basically what I am trying to say is use #12 or larger wire if you are running to your battery. And its the length of both positive and negative. Current in DC flows from neg to positive.