So I was driving in to town this evening (after dark) and about 10 minutes into the drive my radio started cutting in and out, then the instrument cluster lights dimmed and failed. I hadn't had any trouble starting, except for needing a jump the other day. I was worried when I had to jump it, but it has started up fine since then. Well, I got to where I was going, and happened to run into another 300D entusiast. I let the car run while I was in the store for fear of it not starting again. I talked to him, and we shut it off since I had cables, and voile! no start. Couldn't jump it either, actually didn't have the time to charge the battery. The car is a greymarket 84 300D wagon, normally aspirated. The alternator looks brand new (I just bought the car and the guy did make mention of replacing it). I wound up leaving the car and am going to go jump it with my Dad's cummin's tomorrow, but was wondering where I should start looking for problems? Is there any way to test the alternator (lick my fingers and grab it?

Where should I start looking for wiring troubles, or what should I look for? Everything appears to be connected and "normal." Any advice? How much does a new alternator cost? I would put it in myself, seems easy. Thanks,
Will lyons