What is this

[81 shortbed]

What is it, what does it do, and do I need it?

[emsvitil]

Capacitor / Condensor

Is it hooked up to ignition?

It's for radio noise.         

[81 shortbed]

the wire disappears into the main harness. when I wired the radio I just ran new wires cause it didn't have the factory wires anymore. guess I don't need it. thank you, sir

[emsvitil]

I'd keep it.

They are to quiet ignition noise from affecting the radio.       It's not directly connected to radio.

[OOPS]

Not hurting anything, leave it alone!!

[86bobbedtoy]

they came on a lot of the older toys, usually they were connected under the coil tab