That sounds awesome. Maybe I'm just sheltered, I have never even heard of a switch that does that. It sounds like a really useful feature, did All the 94 and 95 dodge trucks have the switch?

 

A lockup switch is a add on we can do to the lockup 47rh/re an 48re gotta wire it in but its a simple thing to put in if your embarking on the journey of what your planning . A buddy of mine is wanting to do the same so when he an I pull the trigger ill prolly have a post about it however I have no idea when that will be. His is a 1990 W250 rig.

 

If you ever want to intercool your truck I'll sell you my stock intercooler and pipes if you want

 

In case you're having trouble picturing an electrical switch affecting a hydraulic component, picture a couple of comparisons: A manual tranny, with a clutch pedal gets disengagement pressure from your foot on the pedal, and engagement pressure from its springs. The lockup clutch in a modern automatic tranny gets disengagement pressure OR engagement pressure from hydraulics. Fluids travel thru plumbing and valves. The valves are pushed open or closed by pressure (and springs) coming thru yet other valves. Eventually, you find the place where there's a valve controlled by a solenoid. The "mystery switch" or "magic switch" or "lockup switch" powers or de-powers that solenoid. Fortunately, you don't have to fingertrace all the internal plumbing passages! The solenoid for that is on the outside of the tranny, and all the rest of the magic has already been designed. :-) It's all about manipulation of fluid pressure.