Duramax_06

alright guys and gals any help is appreciated. I have a 2007 Chevrolet Silverado 2500hd LBZ. Just recently I found out I had no reverse lights. All the fuses are good. I have no power going into the bcm telling my reverse lights to come on. I can jump power to the light green wire at bam and my reverse lights work. Does anyone know the wire color going inside the transmission to IMS switch(P/N safety switch) and the wire color leaving the switch? and should the voltage going In and out be 12V? I don't know if I'm losing power somewhere or if the switch is bad. The switch is internal not external. Thanks in advance.