LED bulb help! Won't work!
 

Attachment 25229
Had to solder a piece of wire back on, and it still won't work. Does it matter which piece of wire goes in which hole of the black plastic cap?

I assume this bulb is a switch back. Identify ground first. Then individually touch the other wires to a 12v source. Did it not come with a diagram of some sort?

If it did I don't have it, and yep it's a switchback

Wear gloves bro

Fixed that for you ;)

Get a cheap replacement from ebay and be done with it.

Why? They are LED's, they are unaffected by oil on your fingers like Halogens or HID's are.

To OP: LED's are polarized so they only work when connected in the right direction, from my guess the lead with the diode on it (that little black cylinder) needs to be connected to the ground (common) wire which is usually the black wire. Then the other three activate the different LED Clusters.

Im curious... What bulb is that for?

It's a switchback turn signal.
I tried switching it around, I have LEDs in other spots so I get that part.
After trying it several different ways, it blew something, cause my rear tails, parking lights, and side markers don't work. Checked and double Checked all fuses, those are all good. Blinkers headlights and brake lights all work.

Yes, do not actually test electronic items in the car. You should always use or separate power source (or directly from the battery terminals). As far as whether the bulb is blown or not, it really depends on the components used to build it. I know some LEDs can handle a small amount of reversed polarity. These are SMDs though so I'm not exactly sure what they would be able to tolerate.

Although a switchback should only have two functions, I see four wires. I've never played with one so I honestly don't know. (kind of irrelevant though)

I'ld say to find a 9v battery or a little 9-12v wall power supply (like for computers and other chargers). The one with the resistor should be negative so touch that to negative, then touch the others one at a time to positive. I'm sure you've already tried that, but it's all I got.

Where is the wedge socket? If it broke off I'd just replace it.

If it is a switchback then it contains two circuits. That requires 2 hot wires and one ground. Look at the band on the diode. The end of the diode with the band on it indicates the direction of current flow. I'm going to guess the band indicates current leaving the device, in which case it is ground. So try red on either plain wire and ground on the diode wire.

I'd just jumper off the car battery to test as it is the only isolated 12v source you probably have access to.

Really unless you want to tinker, I'd just toss it.

I paid $45 for these switchbacks- I hate to throw it away. There needs to be 2 wires on each side (once I put the black cap on it). We tried it several different ways, and it never would work. Just trying to figure out what side each wire needs to go on when folded down. Hope that makes sense

Here is a pic of how it was before the black piece was off. Had to solder the missing piece back on. I need to figure out which wires are on which side. Yes I can do process of elimination but I don't want to blow another fuse

Woops forgot pic Attachment 25298