From Mike, who got me in touch with Tommy... Thanks Mike and Tommy!
On the 1998 Dodge Ram 1500 V6, there is a 43 dollar ABS speed sensor that cuases the following list of problems when it breaks...
Check Engine light,
Parking break light,
Trans won't shift properly
Speedometer won't work until about 25 mph
Here's the story straight from Tommy,
The dash was lit up like a christmas tree, engine light, ABS light and even the parking brake light. Also the transmission shifted late and irratic. The speedo also didnt work until you reached 15 to 20 MPH. So it spit out a code that said "output speed sensor." So yeah I got the part, some ABS speed sensor that goes in on top of the rear diff and it was 43 bucks. I put it in and everything was back to normal. I was really surprised about the tranny problem being corrected I thought I was going to have to start buying solenoids and trouble-shooting, but it works great now.
Look at all of these identical complaints about this part failing! http://www.dodgedakotas.com/boards/dea/168-3.html
Looks to me like the 26,000 results on Google searching this all come to the same conclusion, lousy part that gets the same seemingly unrelated problem lights on the instrument panel, and the speedometer and trans problems