Car won't crank, Guage lights flash, and how do I pull my starter?

I guess you know that looks like the starter has been changed before.
That yellow crimp on the solenoid wire is a give away.
Not factory at all.
It also looks like you can get to the wire and the main battery lead there.
Like has been said, bad connection somewhere above is most likely.
I'm confused about this "flashing" light thing though.
I suppose you mean when you turn the key those things go off and when you let the key go they come on?
Yes, low voltage somewhere.