Alright, I am putting a two stage setup on my car and I am using the dynotune 2 stage rpm window switch. I want to add some LEDs to let me know when each stage is activated. Kind of a way to know both are going and not just one and such. I plan on putting a LED inline on the wire that comes from the window switch to each stage solenoids.

From the threads I read on this type of thing people talk about adding a diode inline to the LED, is there a certain size diode to get or anything? Or would I get away with just putting the LED inline and grounding the other side without a diode?

 

In your case I would use a 900 Ohm 1/2 watt resistor before the LED(For each LED). Here is a link that might help. http://www.quickar.com/ledbasics.htm