[RIP]

Sounds like the van went into what's called limp mode because a problem was detected in the transmission or it's sensors. It won't shift above second gear. This helps prevent serious damage to the transmission. Hopefully your service engine light came on meaning you have a stored fault code. Even if it didn't you need to read the codes. I think 95s still used the old OBDI fault detection system so a scanner won't help. OBDI scanners are a rarity. You'll have to do it manually by cycling the ignition key from off to on (not start) leaving it on. Now count the number of flashes of the service engine light. All codes are two digits. For example code 21 would be flash, flash, pause, flash. Muliple codes are divided by a longer pause. A code 55 means the test is complete.

Besides that you can inspect all the sensor connections for security and corrosion. You could try resetting the tranny by disconnecting the battery. Just remeber when you do that any codes will disappear.