Shift light for hp tuners
#2
not sure what your asking...if you are scanning with hpt you can just set the tach gauge to light up at any rpm you desire and make that gauge large and you wont be able to miss it (gauge display screen)
#3
There is a feature in hp tuners so you can use a external shift light and control the setting through the pcm. I've found some info on wiring it up, but nothing specific about which light