Anyone running a Harlan Window switch and fuel pressure safety switch?
Could I be trying to ground too much? How to test with meter?

Specs
Dimensions: 1" diameter by 3" long
Housing: Flat black painted Polycarbonate tube
Usable on all ignition systems (distributor, distibutor-less, 2/4/6/8 cylinders)
Adjustable in 100 RPM steps from 500 RPM to 12000 RPM without additional pills or modules
Operation and Installation instructions included. Check them out.
Grounding output capable of sinking 0.5A of current

 

here is the diagram NXRicky I think did for me

 

Look at #4, it says courtesy of "xssive"

https://ls1tech.com/forums/nitrous-oxide/501965-nitrous-related-wiring.html