No Brake Lights!

Help! New (to me) '93 suburban w/ otherwise pretty unmolested electrical system...but i just noticed the brake lights aren't working. I've tested the pedal switch & it's good. I've checked the leads at the tail lights w/ a test light & could not find ANY signal coming from the brake switch. Guess I'm looking for any (or all) of the following:

1. A good wiring diagram for a '93 Suburban 1500, 4wd, etc.
2. A component locator to accompany item #1
3. Information as to how the signal from the pedal ultimately hits the lights....via relay & through the turn signal switch, yes? If so, where's the relay?
4. Other pointers, tips
5. (related to #4) if it's the turn signal switch that's bad, a) how do I test it & b) what's the best way to remove it (I'm assuming the wheel comes off & all the wiring slides up after it...yes?).
6. Comiseration, sympathy, etc. for having such an otherwise nice truck w/ no darned brake lights!

Thanks in advance.

-chris