sound goes out w/in few secs of power on

Actually, I should point out that I discovered there are 6 speakers--2 tweeters on the dash, in addition to 2 mid/woofers in the front doors and 2 in the back. One of the RF wires (call it the RF+) to the tweeter is reading short, as well as the RF+ wire to the right front door speaker.

Sounds like you definitely have an issue in that one. You could just run a wire to the footwell, connect, and hope. Or, pull the tweeter, and connect as close as possible to it, (be sure to keep any high-pass devices in the circuit - a cap most likely) and do the same for the door - the door will not have a cap. It's gonna involve some work anyway you do it.It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."