lights can be wired any way round, there is no positive or negative
if fixture has two bulbs then two blacks are hot wires. Two whites are neutral wires.
Connect black to black and white to white from the switch. Your old fixture may have had wiring for multiple bulbs so they could be switched separately.
This sounds like a typical light switch connection that turns on an overhead light fixture. There are two pairs of wires in from the supply voltage and two pairs of wires out to the light fixture. The two white wires are connected together in the back of the box. These are the neutrals from the supply to the light fixture. The two black wires are the ones that get attached to the switch. Incoming "hot" to the top terminal of the switch and the outgoing black to the bottom terminal of the switch. If you just touch the two wires together as you explain in your question then the light fixture should come on.
You would have to provide more info to be certain what your problem is. Typically a black and white wire would connect to the two wires on the light fixture. The fixture should also be controlled by a switch that "breaks" the black (Hot Wire) to turn off the fixture. If you have a volt meter you can see if there is 120Volts between the black and white wires with switch on. If there is a single white wire going to fixture (Neutral), where is the "black wires tied" to. Maybe one of the black wires has broken off the fixture.
Connect the white and black wires back on to where the other black and white wires connected. There should also be a green pigtail coming out of the fixture which will be the ground. If it has a chain, then the wire running through the chain will be the ground wire.
Yes. Connect Black to Black, White to White and bare ground wires together.
if fixture has two bulbs then two blacks are hot wires. Two whites are neutral wires.
Connect black to black and white to white from the switch. Your old fixture may have had wiring for multiple bulbs so they could be switched separately.
This sounds like a typical light switch connection that turns on an overhead light fixture. There are two pairs of wires in from the supply voltage and two pairs of wires out to the light fixture. The two white wires are connected together in the back of the box. These are the neutrals from the supply to the light fixture. The two black wires are the ones that get attached to the switch. Incoming "hot" to the top terminal of the switch and the outgoing black to the bottom terminal of the switch. If you just touch the two wires together as you explain in your question then the light fixture should come on.
You would have to provide more info to be certain what your problem is. Typically a black and white wire would connect to the two wires on the light fixture. The fixture should also be controlled by a switch that "breaks" the black (Hot Wire) to turn off the fixture. If you have a volt meter you can see if there is 120Volts between the black and white wires with switch on. If there is a single white wire going to fixture (Neutral), where is the "black wires tied" to. Maybe one of the black wires has broken off the fixture.
If both wires are black then the one with the writing is the neutral wire. If the two wires are black and white then the white one is the neutral.
If these are all the wires you have then this would be a great assumption. It assumes also that everything before the fixture is wired correctly and with commonly used color schemes.
Connect the white and black wires back on to where the other black and white wires connected. There should also be a green pigtail coming out of the fixture which will be the ground. If it has a chain, then the wire running through the chain will be the ground wire.
Wiring a 2 wire fixture to 4 wire outlet depends on configuration of wires in outlet box. If you have 2 white and 2 black I will assume there are more lights controlled by the same switch. 1st scenario attach both black wires to black of 120 volt fixture. Attach both white wires to white wire from fixture. atach ground to box or ground wire. 2nd scenario attach white neutral to white from fixture, Attach black hot to white going to switch. Attach black from switch to black from light Fixture. If you need further help I recommend hiring a contractor. Take a look into contraxtor.com
The standard is: the white wire is "Neutral", and the black wire is "Load".
If both wires are black, the one that connects to your white wire is the one that should have little writing on it. Black to the plain black wire, white to the wire with writing.
If the ceiling fan has a light fixture included in the fan, then there will be three. A white, black and blue. The blue is for the fan if the owner wants the fixture to be switched individually from the fan. Other wise there are only two wires to connect to the fan, a black and white.