doghouse

hello all!!! i am lookin to add an amp to my 2006 gs300 , i need to find a wire that i can use as a remote for the amp, usually its the blue wire that you connect to the amp from a aftermaket radio, i have the Mark Levingson package, i notice the amp is in the side of the rear trunk may i can splice in one of the those wire but which wire??? any help and suggestion is appricated!!!

THE.K.W.C

get your self a multi meter and test the wires to find a 12v acc