I was driving in the rain yesterday. I just bought the car, it's a 1991 240 Sedan, 5 speed, and it doesn't have a belly splash pan on it (previous owner removed it, I ordered a new one and am waiting for it to arrive). I was driving for about 5 minutes and suddenly I notice the dash warning lights fading in and out, and when I'd turn the steering wheel it the dash lights would come on immediately. I also noticed a really weird clicking sound that would happen for 5 seconds and then stop for about 20 seconds and come on again, then repeat the cycle. So I pulled over and couldn't pin point where the sound was coming from. I assumed that the alternator was dead due to the dash lights turning on and off. I decided to turn around and go home, a couple minutes later I look down and notice my temp gauge is almost to the top, so I pull over and smoke starts pouring out from under my hood. The top hose on the radiator came off due to the lip being broken off, apparently the previous owner just clamped the hose on really tight after it broke off and thought that that would hold it together. After I put the hose back on and added the coolant I limped home which was only 2 miles. I tested the battery, it's 12.58V when the car is off and 12.1V when the car is on. I just started the car and the clicking noise is extremely loud, and constant, and definitely seems like it is coming from the alternator. I have uploaded a video of it to youtube, the video itself sucks, but hopefully the audio can help someone pin point what it is.

I am a rookie at repairs, to me it seems like the alternator is dead since the car is reading 12.1V with all accessories off, but maybe I'm wrong. Would a dead alternator be making this kind of noise? I'm assuming it got soaked from water splashing up and possibly some of the coolant might have dumped into it.

Here is the video: http://www.youtube.com/watch?v=T2P_DAOquPw

If that link doesn't work just copy and paste this: http://www.youtube.com/watch?v=T2P_DAOquPw

Thanks for the help