No Power to the interior CAB of the Vehicle, What can cause this?

OK, I checked all that and repaired another fusible link and there is now power. Now car will turn over, but not start. Any ideas?

Yes the car has been sitting for a while, it has a 2.8L V6 engine. It just cranks.

Sorry for the late reply, it has been more than I imagined with the car. Ok, so update: Had to replace the fuel tank, fuel pump, and pulsator. The tank was rotted bad and the fuel pump and sch were shot. Thankfully it never blew any of that through the injectors so they were fine. Replace all the fluids, spark plugs and wires. Also replaced the distributor cap and rotor. Car fired up and ran for about 50 miles. I now know the IAC valve was sticking and I cleaned it and it seemed to work better. However, now there is a really bad oil leak. I initially though it was from the oil pan gasket (which I forgot to replace), but once I removed the starter, I noticed the oil was leaking from somewhere above the transmission housing and running down onto the starter and ground. What can this possibly be? There is no oil on the flywheel, just seems to be running from something on top. Please help and thanks in advance.