After market switch wired to transmission control module
 

I recently bought a 92 so that's been modified
I noticed a switch in the dash was there. I didn't notice anything when I switched it. so I followed the wire and it's been spliced into the module. curious if anyone may know why?

I have wiring going to the TCM on mine that I added. I wired mine up as a first gear lock out. When I am in 4 low, the shift to first as I slow down is like hitting a wall. I wired mine so that it only works when the selector is in the 1-2 position.

Some guys have them wired to hold it in first gear.