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ice_it_06

12V light wiring

8 posts in this topic

Attempting to replace two old style screw in ceiling lights with a RV type & LED bulbs.

After removal of the old poresilin base it was noticed they were wired with house wiring. Two contacts on the back of the base with a "white" lead running to each and one side had a brown on it as well.

There appears to be (2) seperate lines running to this recepticle with a white on each contact and the brown "spliced together" and a single lead comming out of that splice and connected to the one "white" contact on the base ?

The + - is not marked on the base and I'm not sure how this thing is wired up. Is the (white +) and (brown -) ? Cant see why they would "both" be connected on one terminal ?

**note** the house has (2)double receptacles on the outside front. A jumper from the truck battery goes to one, and then there is a jumper outside connecting the two receptacles.

Inside under a bunk lays a jumper cord with + and - connectors. This jumper is (hot) as I plugged in portable 12v accessories to check it, and everything else wired within the house walls (ie switches,hole lights,receptacles,lights) all work through this connection from the outside. I'm wondering if I hook up a (Deep Cycle)inside on the jumper under the bunk if it will power up the entire house and if hooked up to the truck outside if the truck would in turn charge this battery inside seeing the cord is hot when connected to the truck !!

Also, is this type wire "overkill" for 12V and cause of delayed or lost power due to the guage of wire and long runs ?

If anyone understands my mess (lol) help me out with your thoughts.

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About the size wire it is overkill it may cause problems with a low battery.

This last week I was helping a friend put in a 240v air compressor. Last summer he wanted to run two sets of wires one for a compressor and another for a welder. The compressor came first, we opened up the breaker box to find that neither one of us labeled the wires coming in blush.gif. The breaker box is on one side of the garage and the outlets are on the opposite side (20ft away) approximately 15ft apart. We could not just use a muli-meter and check for continuity, the leads are way too short. So, I thought that hooking up a jump pack that would be safe enough to check for power. I first tested the jump pack it stated it had 25% of the power, I hooked it up to my 12v light directly and it worked just fine. I then hooked it up to the 10 gauge wire coming from the breaker box, the light should have came on, tested both sets of wires. I also tested it with the multi-meter and I could not get a reading, nothing, from either wire. I then checked the jump pack and now it read 5%, it still lit up the light when connected directly, but, it could not push enough juice through the 10 gauge wire. So, in my experience, the wire you have will cause a delay and require more power.

Granted there was 30 ft of wire the jump pack had to travel, you may not have to go that far in your setup.

and about the wiring for the lights, I know with 12v lights when used in a trouble light it does not matter which power lead goes to + or -. I would think that when the lights are in a series, as long as the light fixtures are wired the same it does not matter which one is the + or -. Someone else chime it and prove or disprove my theory, I am going to try and wire up some 12v lights to see if it does matter this weekend. Bulbs are cheap. I can handle losing some wire, granted it will be a smaller gauge wire that you are using, with any luck it will work without problems, I will be putting in a fuse just in case I run into technical difficulties. grin.gif

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If you wire your lights in series and one burns out, they all go out. wink.gif

Polarity won't matter on lights in a 12V system as mentioned.

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Well I'm far from a 12v expert at all but thought installing a RV type fixture in replace of the old house bulb style would not be a big deal.

My only issue is why there was a white & brown lead on one terminal together, and just a white on the other terminal of the receptacle base.

Will have to use the marker lights I have to test these leads I guess and try to see whats up. Have a 12v fan I could use where polarity wont be a issue if I mess up trying to figure out the (4) wires in (1) fixture connected as they are ?

This house is used and all prewired with house grade wiring so we're screwed there. Might just have to run new wire in a channel along the base boards or ceiling to the areas we want new LED dome lights instead.

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After further inspection it was found both these leads contain (3) wires inside the gray insulator. Black, White & Brown.

One White from each leads to the fixture, both Black are spliced together, and one brown connects with one White on the fixture, the other brown was just snipped off deeper in the insulation.

I connected my 12v fan to the White leads and it fired right up. Depending on which leads dictated the fan "pushing" or "pulling". The wall switch cuts the fan off as it did the light, and the wiring does not get hot.

What the "brown" wires purpose is I have no idea. The amount of "draw" on the fan speed was crazy when I turned on other lights of the old style 12v screw in so I really have a major power loss set up as is.

Plugging in (2) different LED lights of over 50 bulbs each did nothing to the power draw at all with everything else running or on @ the same time. LED is the only way to go IMHO.

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Using wire larger than necessary (or just of a larger gauge) will not cause more/excessive battery drain. In fact, thicker wire could, in some instances, marginally reduce battery drain since less power will be wasted as heat due to the lower resistance of larger wire.

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Yup. The heavier the wire, the less resistance you will have and like was said there will be less current lost as heat. Small wire with high resistance is why the filament in a light bulb lights up and you know how hot they get.

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Well like I said I'm all ears and student when it comes to12V wiring.

The heavy gauge house wire works, just a good delay in lights comming on. Truck running current is right now and strong. Maybe due to the 12' jumper from the car to the house and then 16' house with God knows how much wire behind the walls & ceiling.

The "brown" wire I found connected to the one white was a jumper the previous owner used for connection of the hole lights up in front of the house where this ceiling fixture was.

After getting a new RV dome light installed, I left the brown wire unattatched and of course discovered the front hole lights not working. Reconnected the "brown" wire to the one white hot lead and the hole lights work again along with the new ceiling light and fan installed.

**now I need to get the kid to bring a 12v inside and hook up to his jumpers under the bunk and see if a inside battery will light up the joint.**

It only appears "hot" to those jumpers under the bunk when connected to the truck through the front wall receptacle.

Trying to figure out someone elses set up is always fun when your not real informed yourself !! lol

Appreciate the help here always.. ice_it

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