[Spits] A trip to Wisconsin - radio wiring?

[s1500]

So, I decided to take a trip to Baldwin, Wisconsin to a paintball field 
to hang out with friends & such. Decided to take the Spitty down since I 
paid so much for insurance(okay, 300 bucks), I might as well get the 
most out of it.

Overall, things went pretty good. It used up more fuel than I wanted for 
a 30-mile trip, so I knocked the fuel pressure regulator down by a half. 
The result was quite a bit less fuel being used on the way back.

Hit a puddle on the dirt road out, and got stuck for a bit, but eased my 
way out. The only damage was a busted muffler mount that was rubber + 
rope construction. Time to make a metal one.

Day later, I bled out the rear brakes and found out the adjuster on the
rear right was seized, making brake tuning almost impossible. Some
greasing(a VERY light amount, clear of the pads) and it was going again. 
Now I just have to address the tranny fluid leak, or if it's just messy.

Anyways, my question for the forum: Any place I can get info on car 
radio wiring diagrams? My google searches so far have found nothing, 
with the wiring diagrams really not even mentioning a radio. I know 
there's pairs of wires for each of the 4 speakers(thus at least 8 
wires), but there's more for the power antenna(don't have), and such. 
It's a bit of a mess of wires down there and I want to sort them out to 
fix my volume problem once and for all. I'm from 4 speakers down to 2 as 
the PO's wiring job for the speakers wasn't up to par.