Chevrolet Repair: Electical problem, bump in the road, ground wires

Question
Ok, well I read alot of the questions that other people have asked. It seems that there are many people with my same problem. I have a 97 Astro cargo van that has a very odd electrical problem. It started with the dome lights not shutting off, then the winsheild wipers would not shut off, then the instrument panel would shut off along with the radio and tail lights. Also the van will shift very hard into second gear after it has been driven over 20 miles. Sometimes the gauges would all work fine, then you would be sitting at a light and they would all shut off. And ofcourse turn on whenever they wanted, it doesnt take a bump in the road or a turn to make this all happen, you can be perfectly still and it will happen. I have traced all of my ground wires and inspected all of the wires in the harness. I have proper voltage to everything. I did notice that if i unplug the instrument cluster, the radio would work again, not sure what thats all about. I do know that all of my problems are related, tranny, gauges, lights... they all started at the same time. I guess my question is : Is there something that causes this problem in these vans/cars frome this time era? Like I said, ALOT of people are having similar problems on this site and they are all getting different responses. I noticed some circiutry under the dash and I have no way of testing these and have no idea if they could somehow be the problem. Please get back to me with the best answer that you have. Thanks, Beau

Answer
Is there something that causes this problem in these vans/cars frome this time era?
Yes
GHOSTS
Ha Ha . Just trying to make light of a serious situation.
Try wiggling the smaller wire going to the starter and see if you get the same results you would if you were driving the car.