A somewhat crude drawing of the wiring and plumbing of the D2 Governor and how it ties in with the compressor clutch. It's really quite simple and far more compact and durable than any other set up out there since these are for over-the-road trucks. The red lines are the only air lines in the control system and the rest is wiring. You can see that one red line goes to the air tank and the other is where I installed a pressure gauge.
![Thumbs Up :thumbs:](https://board.marlincrawler.com/Smileys/marlin/thumbs.gif)
The gauge, of course, can be plumbed pretty much anywhere.
Also, unlike the pressure control switches other people have used that are for a home compressors and aren't designed for this sort of environment under the hood these are built to be used in this way. 8)