So I know the ignition switch controls starting your car. I also read somewhere that it is also the main power source. I plan on replacing the switch this weekend, but my question is do you think that it might be the cause of other things...like my cruise control not working, my window acting funny, or my locks not working properly?

 

Probably not, for those things.

Ignition switch has only 3 circuits running through it.

- Accessories circuit switches on lots of stuff like radio, etc. This is energized in the ACC position and in the RUN position. It switches off when the key is turned to the START position.

- "Ignition" circuit powers the ignition (sparkplugs) and the fuel injection, along with most of the sensors for the engine, some other things like the instrument cluster, etc. It doesn't come on in the ACC position. It comes on in the RUN and START position.

- Starter circuit provides the signal to the starter solenoid. That's the small wire to the starter, not the huge power wire.

So if one of the circuits were bad, you'll lose a whole lot of stuff together. Not just cruise control. or windows.

More likely something flaky is going on in the fusebox or further "downstream" after all the different circuits have become separate from each other.