I planned using the 1/4" male spade "IGN" lug in the fuse panel for the nitrous activation switch. However, my bottle heater also requires a switched 12 volt source and I do not want to overuse the "IGN" circuit. Is there another convienent switched 12 volt source? I heard there is a switched 12 volt source in the radio wiring harness. If this is the case, would anyone know what pin and corresponding wire it is? Or am I limited to the trial and error method with a test light or DVOM? Thanks for any help offered.

 

I used a Bosch relay to draw power from the battery to a fusebox that powers my opener and future warmer, powered by an on switch that draws power from the ignition fuse panel. Wiring is near the bottle with 12 pin quick disconnects.

 

Use the "switched 12V" power off the "IGN" fuse only for "signal" voltage to the nitrous solenoid relays, and to the heater relay. Supply the heavy direct load to the solenoids and the heater via separate fused circuits direct from the red positive box near the battery.