My '82 Chevy G20 5.0L van won't start. I put in a new battery (probably not necessary) and the lights work, but nothing happens when I turn the key (the accessories won't work either: for example, the fan does not com on when I turn the key.

Any ideas? I know that electrical problems can take a while to pinpoint, which is why I'd like to keep it away from my mechanic.

(I was guessing that the ignition switch itself is shot).