I am trying to wire 7 LEDs together, and failing.
Lights: (Numbers are for image below, I have no clue what other info to put here, so I just made them links) They are 3V.
Lights 3&4
Lights 1,2,5,6,7.
Resistors: 
I think this is 100M ohms (It came marked as “5.1-9Vdc use”)
Battery: 9V With battery adapter. I have tried multiple batteries, so this is not the issue.
I am trying to wire these together, and read that parallel is the best way to do this. I kind of did a series/parallel mix.
I think the best way to explain this is to show an image, and than say what's not working, hopefully you can help me out 🙂
Key:
Red: Positive wire/power
Yellow: Negative wire/ground
Blue: Resistor (I think it is 100M ohms.)
White: LED (3V, 3&4 are white, rest (1,2,5,6,7) are warm white)
Pink: Battery (9V) and mess-up number
Only LED #5 works here, and it's nice and bright. Others are off or super dim.
LED #5 is full strength (The only one lighting up this bright out of all the diagrams below. I wish the rest could be this bright), and LED #3&4 are on but dim. The rest are off.
Everything is on (Except for #5, but it's not plugged in), all are a little dim, but not much.
Again, any help would be appreciated, thanks to any ideas!
Also, I guess I should note that I've only been doing this for about 2 days, so sorry if the answer is obvious.
Best Answer
LEDs don't act like ordinary incandescent light bulbs. When lit, they have a fairly constant voltage drop that varies slightly with current. White LEDs have a typical forward voltage of about 3 volts.
The single #5 LED will draw enough current from the 9 volt battery to pull the voltage down to about 3 volts. The other LEDs which are connected as two LEDs in series, will require about 6 volts to light, but since #5 is holding the voltage down to ~3 V, they will not light.
When you remove LED #5, the voltage will rise to allow the other LEDs to light - but the 9 volt battery cannot deliver enough current to light them to full brightness.
LEDs should never be connected directly to a voltage source - they always require something to limit current (normally a resistor).
You should connect one of the resistors you show in series with each series pair of LEDs. That resistor is probably 100 Ohms - definitely not 100 MegOhms!