[Tom Goldman]

I have used the pressure switch Folk Race Cars sells and also the one that Alan listed the link to .
Both work , the Transducers Direct one is way cheaper and I think easier to adjust .
I used the 250-1000 psi set point version.
I incorporate a safety switch in the 2 Step circuit by using a micro switch on the shifter to open the circuit when the shifter is not in 1 st gear .
E-Shift is a little trickier ,I use a relay activated by the controller to cut out the power in 3 rd gear.