'96 Dodge B3500 ... Any Idea What This Button Does?

[eljefino]

I think part of the reason for this button is because OEM's were cheap and were retrofitting 3 speed column shifters (and console) to now handle 4 speeds. It was easier to add a switch, apparently, than to redesign mechanical bits to get 4 detents. Never underestimate the desire to avoid doing work... or spend a cent. Plus by the time the overdrives were popping up, it was becoming the norm to have some level of electronics, so it kinda integrated...

All this, plus marketing. If you were new car shopping and moving from a 1981 C6 to a 1991 E4OD and its "computer controls" you want that pushbutton. It's like the push-button 4x4 transfer cases-- so easy, anyone could do it, even if it was just an elegant user interface to a bunch of vacuum motors and other regular mechanical bits. Just imagine Suzie Homemaker getting her first S15 Jimmy and its "easy to use" fuel injection, automatic, AC, and pushbutton traction vs the rusted out, manual steered International Scouts that previously defined sports utility.