1994 GMC C1500 Tranny and speedometer quit!

My husband drives a 1994 GMC pickup that has a few "kinks" but nothing we can't handle. Yesterday he was driving home and when he slowed down for a stoplight the speedometer suddenly went to 0 long before he was slowed down that much. When the light turned green and he went to take off, the truck got to about 30 mph and redlined! It is an automatic but refused to shift out of 2nd! He slowed back down and tried again with the same result. He had to drive home doing no more than 30 mph. The kinks the truck already has are: the gas gauge doesn't work, when you put it in gear the gauge doesn't tell you what gear you're in such as Park or Reverse - the little orange thingy doesn't move, and he has no air conditioner. I hope you can give us some insight as to what do to next. He checked all the fuses and they seemed fine. Any suggestions would be GREATLY appreciated!!

Thanks so much for your time and consideration,

Shannon Lewis