I have a light fixture that no longer works after a space heater blew the circuit. I removed it from the ceiling and it looks like a few wires were burned. i was able to connect the black and white wires with the caps but now i have 2 blacks and a white i dont know what to do with. Can i cap them together??? the light does not come on still so i believe these 3 wires are important. see attached pic.
Firstly, some safety points/observations on your content...
- Never, EVER, EVER, connect wires if you do not know the original connections without some pen & paper research, testing, and writing down what goes to what
- If wires have burned, there are safety concerns to observe. Did the wires burn at the wire nuts ONLY (due to high resistance), or is the circuit overloaded and the wires melted due to too much current being pulled over an overloaded circuit? Again, this is paper and pencil work. What wire type is it? Looks like a standard copper 15 Amp circuit. Ensure the breaker is 15 Amps not larger, add up the demand on this circuit, are you trying to get more than 15 Amps from it?
- Has the breaker been tripping often? How many amps is the space heater?
- Due to the fact you've noted the wires are burned, make a list of all of the things on this circuit, and check the wires where the heater was plugged in, here at the fixture, and any points up to the panel, including looking at the wires for this circuit INSIDE the panel. If they are crispy and melted/burnt, you will need to replace the run
- I'm glad you pointed out the sheathing missing on the wire, you need to check if the sheathing is crispy or broken elsewhere, all the way back to each of its connections. Do not use the wiring if it is. If it is only here, and CONFIRMED only here, you'll need to tape it/replace it.
- If this is daunting, it would be best to hire an electrician to come in to do the repair, safety first!!
Most likely yes, the two blacks belong tied together (the whites probably do too.... but this all needs to be validated), but since the circuit blew, and the light no longer works, we know something in the circuit is not working. The burned wires need to be replaced. This is an indication that some other weak spot (at additional wire nuts, or the panel, or the breaker, and it could be hot or nuetral side) is broken/dangerous. You really do need to check it all the way back. You really do need to make sure you aren't exceeding the circuits capacity. Also, ensure the breaker is the right size. My post here is somewhat redudant, but it is very important to do these checks.
You need to verify a few things before just connecting white to white and black to black. 1 Set of wires may be a switch loop, 1 from the supply from the breaker and 1 to the outlet. If this is the case connecting everything together will blow the breaker when the switch is turned on. What could cause this? One of the wires in the wire nut was loose and probably arcing with the heavy load enough heat created to melt the wire nut this can happen even with the proper sized breaker. To fix find the hot cable, identify the cable going to the outlet, the last cable check for continuity with the switch in the on position if good verify it is open with the switch off. Now time to connect back up. Connect supply white with outlet white and lamp white. Next supply black with outlet black and switch white (this white to the switch should be remarked a color other than green,white or gray) putting power on a switch leg white is recommended so it is easier to troubleshoot later. Connect the switch black to the lamp black and all the bare grounds together and you should be good to go.