92 Tercel Dies, need help plz!

I recently purchased a 92 Tercel for only $500 (canadian) with a shot piston (4 cylinder), the guy told me it had about 5 months life left, whether it did or not i dont care, as i only paid $500 for it. Point is, I live in an exteremely cold climate at the moment which lows of -40 at night. At one point I had nowhere to plug it in, so, as you'd think it, the battery died and it wouldnt start. I waited until a warmer day came around and it DID start and worked fine.

Now, the cold weather is back and i've had the oil light constantly coming on. At first it would only come on when it idled at low rpms of around 800, then it got worse and it would stay on until 1500 rpms. I was hearing a strange rattling as i was accelerating, but it went away when i was in neutral.

And so tonight, i was driving along and i noticed i wasnt getting any power in 3rd, it just died. I pulled over, it fired, and i went a little further it died again. I tried to fire it again, it wont even turn this time, you just hear that dead thump when i turn the key.

I have no clue, is my engine seized?? if so, it wouldnt of turned over the second time after the initial stall right? Im figuring it couldnt be the battery again because all my power was going (upon stall) and i could us the 4 ways, the only thing i have noticed power wise is my lights get brighter when i was accelerating, and dimmer upon low idle.

Any help appreciated, thankyou.

Definitely check the charging system and battery.
Loss of oil pressure will make the motor noisey.

Thx for the reply Kim!

So you figure i've got two problems on my hands, the battery and oil pressure? What do you think caused it to die though tonight exactly, any good guess will do, its just i dont want to get screwed on labor or major assesments :(

If i can pinpoint the mechanic what to look for it'll be cheaper for me!

Not just specifically the battery, but rather the charging system and how it connects to the battery.
Is the alternator putting out the correct voltage?
Are all the conections clean and secure? Plugs and cables.
Condition and tension of the belt?
Battery itself?

If you are capable of removing the alternator youself, some autoparts stores will test for free. In the states some stores will test the alternator and battery under load (best) while in the car.