help!

I have a 1991 S-10 p/u. Last night driving home in a down pour( I live in Seattle) my truck just quit running. No radio, wipers, dash lights, or engine. Couldn't even get the engine to turn over.
Just dead. Although the headlights and the interior lights work just fine. Battery is brand new. If anyone has any suggestions that would be great.

what motor is in it 2.8 or 4.3l ??

4.3 litre

don't want 2 state the obvious, but have u check all the connections? (battery & back of the alt.?) if these r ok, then take out your alt. and have it checked. u could've blown something while pushing a high load (wipers-probably on high, lights, radio, maybe even the heater........)