What's this thing?

[vossy]

What is this:

https://imgur.com/a/Hx511

Mounted on front of engine compartment, and has a few wires leading into it, and then some that look like they goto a thermostat or something mounted on top... The black cylinder.

The red wire, has pulled free of the connector and is not connected on it... I wonder what it does, do I need to fix it.

[DuckRyder]

That is the voltage regulator.

[vossy]

What does it to? The blade that connects wires doesn't seem to really plug into anything.... I took off the sheet metal dome portion, and there is nothing inside..

[DuckRyder]

It controls the charging voltage unless the alternator has been replaced with something internally regulated.

That is a newer replacement voltage regulator, it is likely solid state so it should have a circuit board and some transistors and other electronic magic stuff in it...

[mac6150]

I replaced my old voltage regulator with an electronic one. The one you have contains points and the condenser on top acts as an electric noise suppressor ( may have some other function that I'm not aware of). It helps reduce electronic noise to your radio, that is if you kept the old analog radio.

I replaced the old system with new electronic upgrades, this includes replacing the points and condenser in your distributor cap with electronic ignition system. That is a relatively easy upgrade. Anyway, an upgrade to the voltage regulator isn't very expensive and I may be an option for you.

[Thipdar]

What is this:

https://imgur.com/a/Hx511

Mounted on front of engine compartment, and has a few wires leading into it, and then some that look like they goto a thermostat or something mounted on top... The black cylinder.

The red wire, has pulled free of the connector and is not connected on it... I wonder what it does, do I need to fix it.

Would help us if we knew what year you are referring to.

Take note that there are two different ways to wire the connector that attaches to the Voltage Regulator - the differences are based on whether your vehicle has idiot lights or if it has gauges. Hook them up the wrong way and you'll be making headaches for yourself.

[Ranchero50]

Super ditto.

Wiring diagrams are in the main fordification site. Little difficult to trace since they are layout drawn versus function drawn but it can be done.