Strange electrical Problem

Need help with a strange series of symptoms. We were driving at slightly stop-n-go traffic when we experienced an odd (and a little scary) situation with our '94 Villager. The first symptom I realized was the cruise control acting hinky - not holding at speed. Then it looked like the dash lights/clock were dimmer, blower speeding up and slowing down. Strange hum from the radio. Then engine started surging, slowing, and the tach was going updownupdown - on a whim, turned all electrical stuff, lights, blower, AC, headlights - drove fine. Realized the battery light was on, steady, then on and off. Look again, off. Then on. Realized it was off, and we we descending. Hmm. Again, when we were on an off ramp, going down, it went off. Realized it came on again when I used the turn signal. Also saw that the brake idityo light was coming on - and off. Brakes seemed just fine. Reached our destination shaken but fine - drove OK with nothing running but the engine.

Any clues? Anyone have anything similiar?

I think you should read the Ford forum some of these type vans had similar type problems. They are much more familiar on these vehicles than I am so I would suggest looking in this area.

How old is battery???? Battery can cause strange things. Also check for bad grounds on engine. Just my thoughts.