A kind soul on the canhack.org forums pointed me in the right direction for the pin-outs. This site has connector diagrams and pin numbers for almost any connector in any Chrysler vehicle. The right answer, found here, is pin #s 7 and 18.

Now my new problem is I've got a flaky speaker connection that seems to have come loose while I've been screwing around with all of this. I thought I'd fixed it last night, but it went out again while driving today. I'm hoping I can fix it permanently without professional assistance.