Common ground, or can we all get along together?

[Tripmaker]

My 12V TD internal wireing will be completely separate from my vehicle/trailer tail, stop, turn, lights. I plan to run dedicated ground wires to everything to eliminate ground problems. My question is this. Should both systems be grounded to the trailer frame which will also be grounded to the tow vehicle through the hitch and tail light connector from the vehicle? Or should I keep the inside system separate with the ground only going back to the TD battery / converter? I guess the bottom line question is, is there any cross feed problem between the two systems if a common ground is used?

More than likely when using the internal TD system it won't be hooked to the vehicle so this may be a moot point, but it's easier to ask now than have problems later on.

[madjack]

Tm, running a dedicated ground wire to all circuits eliminates the need or desire to run a common ground to the frame for the interior 12vdc system.........
madjack

[srfrcrux]

so, I am curious about this as well...I will be running my wiring soon???so not to hijack, but just clarify the answers for me as well...
I am running a ground from a fixture to a ground bus (bar)....so a dedicated wire for each fixture to a common G. bus. and then...
Does it need to be grounded to the trailer? floating ground?
Or is what your saying that each fixture need to run to the trailer?
thanks for the clarification,
srf

[Gerdo]

My battery has a pair of #10 wire directly feeding my fuse/ground blocks for my cabin fixtures.

Then I ran a pair (2) of wires from my fuse block and ground block to my first light, fan, or outlet and then continued the pair to the next item on the circuit and so on. I repeated this for each circuit.

My DOT lighting (brakes, marker, turn) is wired to the multi pin connector that plugs into the tow vehicle. I also have charge wires coming from my multi pin. These are a pair of #10 wire. The neg wire is grounded to the frame and continues to the TD battery. The 12v pos hot wire goes directly to my TD battery, thru a kill switch.


I used my TD w/o this charge line for a year. I had no problems with either electrical system (cabin or DOT)

I have had the charge line on for about 3 months, and about 6 trips. I still have had no problems with either electrical system.

I would not change a thing and would do it the same again.

[PaulC]

The easiest way to get you all thinking about earthing to the frame is to consider your TD to be a torch. The internal 12v system only needs to be earthed to the battery. Most call this a floating circuit. The only difference between a TD and a torch is to make sure each appliance is fused.
Cheers
Paul

[Loader]

The internal 12v system only needs to be earthed to the battery. Most call this a floating circuit. The only difference between a TD and a torch is to make sure each appliance is fused.
Cheers
Paul

That's how I did mine Paul. Here is a pic of the initial wiring.

I installed the fuse block, then all my fixture/outlets are connected to the block (notice the pos is to the fuse half, and the ground to the ground bar portion), then I connected battery to the fuse block. I did not use a trailer ground for the 12VDC system.

[bdosborn]

If you plan to charge your battery from the tow vehicle you should ground the battery to the frame and the tow vehicle as Gerdo has done. This does two things; provides a current return path to the tow vehicle for charging the battery and it ensures that both batteries share the same ground reference (so that 12V is at the same level at both batteries). As long as you unplug the trailer from the tow vehicle when you stop, you wont have any problems with one system disharging the other.
Bruce

[Tripmaker]

The easiest way to get you all thinking about earthing to the frame is to consider your TD to be a torch. The internal 12v system only needs to be earthed to the battery. Most call this a floating circuit. The only difference between a TD and a torch is to make sure each appliance is fused.
Cheers
Paul

Hey Paul at first I couldn't understand what you were talking about then I realized we have a language barrier. Torch = Flashlight, Earth = Ground Actually it makes sense. I'll keep my TD ground, er I mean earth seperate from the vehicle system. I don't plan to charge from the vehicle, so that is not an issue. Thanks Guys.

[asianflava]

My trailer lighting, tail/brake are grounded to the frame. I only had to run a positive lead to each of the lights. Because each light is mounted to wood (or fiberglass) I still had to run a negaitve wire but since I grounded the frame, I only had to run a short length of negative.

My DC wiring ia totally separate from the trailer lighting. Each load has a 2 conductor wire going to each item. They are all grounded to a common ground bus which is part of my fuse block. This way, the positive and negative are going to and from the same place.