1994 Buick Century Tranmission not shifting

I have owned this car for a few years, but only drove it for 1 or 2. Here is what happened progressively, as it may be related: First the cruise control stopped working. Within the year my speedometer and odometer stopped working. I tried replacing the speed control sensor, but there was no change. (The ABS light came at about the same time, but I think it is due to a bad caliper) The check engine light started coming on intermittently, and then finally stayed on pretty much the whole time. (This whole time the transmission worked GREAT!) Soon, I started blowing fuses due to a bad fuel pump- I would pull over, change my fuse and keep driving. It was merging back into traffic the second day I had to drive it like this that my tranny scattered. (No forward gears) The fuel pump and tranny were recently replaced, but the transmission is still giving us problems. The first (used) one that was installed would not shift properly and stopped shifting altogether within the week, and would not shift manually. The check engine light is also on. The shop has installed 2 more trannies, and the best we have so far is one that will shift manually only- they cannot get anything to shift automatically, nor can they get the speedo or odo working. They are going to get it onto an OBD1 scanner down the road, as all they have is OBD2, but do you have any ideas?