so you hook up the terminals on the battery and your interior lights start blinking and flashing? If it's a steady pulse/blink then you may just have a circuit open somewhere... if it's an inconsistent/random flicker, you probably have a short...
At any rate, since I'm not a mechanic I can't pinpoint specifically... but I'd definitely would check the fuse box under the hood, check the power levels from the power cable supplying power to the starter. If both those check out to be okay, it could be something different... If your fuse looks good but your power source is short, you may have a short or something on the line drawing power.
Also,
here's another thread that sounds like it may fit your scenario...