Alright, what is the real deal with the "Mystery Switch"? I have done some searches and read some threads on the TDR that gave me the basics. It grounds the TCC lockup wire, causing lockup in 3rd and 4th with a stock transmission. I am wondering what it will do to the tranny if it is left on in 2nd and 1st? Does it harm the tranny in any way? Does it work on a 47RH, or only RE's? What wire do you ground? It sounds pretty easy, if it is, I will try it out tomarrow. The reason for having it is that the 3-4 shift takes FOREVER on my truck when I'm on the throttle, and it doesn't help that the TC isn't locked up in 3rd. Thanks guys, maybe you can make this "Mystery Switch" not such a mystery after all..........