Ceiling Light ground question.

[Leadvox]

I pulled the ceiling lights and redid the switches and wiring. Getting ready to reattach and I noticed that two of the three had ground connections on the aluminum light panel but nowhere to attach them (no ground to the trailer itself). Where should I attach these ground wires? Are they really necessary? (they weren't attached when I pulled the light panel).

[rmkrum]

Gererally:

Sometimes the mounting screws of the 12 volt light fixtures provide a connection to the (hopefully) grounded (negative side of batteries and convertor) shell of the trailer. In that case, one side of the LED or bulb wiring will be run to a permanent fastener (screw or rivet) in the fixture. The mounting screw(s) then provide the ground to the metal of the fixture.

IF your light has a separate 'ground' wire that is connected to the ground side of the LEDs or bulbs, and it's hanging loose, put a ring terminal on it and put it under a screw into the interior aluminum, or splice it to the separate ground wire for the fixture location if there is one...see below...

If the trailer wiring has a ground lead and a supply lead run to the fixture location, carefully determine which one is ground (negative), and which is hot (positive), use a multimeter if needed, and connect accordingly.

LED fixtures tend to be sensitive to which lead is hot and which is ground--read the directions that came with the fixture, please!

[A W Warn]

The light bulbs are grounded through the socket/bulb housing through the rivet that holds it in place on the fixture. The screws that hold the fixture complete the ground for the light fixture to the interior skin. (no ground wires)

The switch has two on positions. One (+) wire goes in to feed the switch. Two (+) wires coming out power some portion of the bulbs (depending on how you wire them - position 1 dim, position 2 bright) There is no ground wire to or from the switch.

The green wire rivet to the light fixture is not necessary to ground the lights but might be a ground through the light. My best guess is, the green wire grounds the fan, to the light fixture. If the fan is grounded a different way, the green wire may not be connected to anything. The (-) wire from the fan motor will have a different color wire.

[Mollysdad]

Looks to me that all the bulbs are grounded through contact with the base and aluminum. At some point the battery negative is connected to the aluminum also. All the positives are paralleled (black?) and go to the light switch.
I'm not a fan of this or trailer lights grounded through the hitch ball.
But it's done all the time.

[Leadvox]

I was very confused that there was only a "Hot" wire coming in and no ground or negative.

You probably saved me a huge amount of time with the ground connecting to the fan, I bet that's it.

This forum Rocks. Thank you.

[Abraham]

Originally Posted by Mollysdad

Looks to me that all the bulbs are grounded through contact with the base and aluminum. At some point the battery negative is connected to the aluminum also. All the positives are paralleled (black?) and go to the light switch.
I'm not a fan of this or trailer lights grounded through the hitch ball.
But it's done all the time.

If you have a standard 7 pin trailer connector, there is a ground pin in that connector, so ground is NOT through the hitch ball. Check your wiring diagram.

Abe