This write up is for gauges that are not plug and play. In my case my autometer phantom 2 gauge needed to be wired in.
First step was disconnect both negative battery terminals.
Second step was to locate the rail pressure sensor right behind the intake manifold, and remove the wire loom and tape to get access to the wires.
Next, I unplugged the wires from the sensor to have a little more room to work.
Next you will want to refer to the install sheet that cam with your gauges. this will tell you what wires to tap into. For my 2006 the signal wire was brown with a yellow tracer, and the ground was brown with a white tracer. I chose to strip back a quarter inch and wrap the wire around it.
Next, wrap the wires in electrical tape to seal and protect the connections.
Next, put the wire loom back over all the wires and plug back into the sensor. It should look like this after wards.
Last step is to add power, ground and dimmer power to the gauges. Then using zip ties secure the wires away from all moving parts. Next plug the connector into the gauge and check to see if it has power.
This install took me about 30 minutes as all my power wires were already there since i removed my volt gauge. add another 20 or so if you have no power or ground leads run yet. Any questions or comments welcome.