gauge wires

[adamm306]

Hi guys was looking at this guide to fitting my boost gauge

http://www.306oc.co.uk/forum/thread-2940.html


all sorted with connecting it to the intercooler etc

quick question in regards to the 3 wires i have on it



am i right thinking the red one can go onto the orange wire under the steering wheel in the coin tray thingy on P1 or would i need to put it on the switch wire of the stereo?

ground is located in the drivers footwell

and lastly one that isnt mentioned on the guide

where would i put the purple wire which is supposed to go onto my "light dimmer"? and where is it located

thanks guys