"system on" light?
 

Being that the DO pressure switch isn't the easiest thing to read, how might I go about wiring in an LED to the system, to light up when the pump kicks on and give me an idea of the psi that the pump is kicking on?

My idea is to have the light go into the back of the boost gauge, so the gauge will light when the WI kicks on.

easy, just take any 3 volt led, and connect it in line with the out going power signal to the pump relay. Make sure that you connect the correct lead on the LED to the ground, and +, if you have it backwards it will not work. Other note, make sure that you add a some resistance to your led. I have some yellow led's that i used a 100k ohm resistor in line with and connected them to a 12 volt sourse for a nice brite light. You can play around with other resistances to get what you want with the type of LED you are using.

http://unclean.org/howto/led_circuit.html this link should help you

here is a quick diagram

I did something like that on my Tacoma. It was annoying though when you make 10 psi at 2300 rpms. I disconnected it.

i have a set of switched below my radio to turn my WI on and off, and to turn my intercooler mist on and off, both have a red and a yellow led.. the red is on when either is turned on, the yellow flashes on when either is activated.

I wired mine ot illuminate the boost gauge when the system kicks in all i had to do was run a possitive wire to the bulb and then piggy back the ground signal i was running from the pressure switch. I then put this on a series of switchs so i cna manualy controll the boost gauge light indepentdent the pump independent or both at the same time via 3 toggle switches this is ht esimplest solution i could think of with the most flexibilty.

Thanks for the replies!