I’m trying to put a new radio in my 2003 Buick century but when I brought the car it already had the wire harness cut out so I brought a new one but the car have 3 yellow wires where they had the radio at so it’* hard to figure which is which need help plz

For about $30, you can get a one year subscription on alldatadiy.com and get all the schematics, diag info and whatnot for your car.

I think there are only 2 people here that have direct GM access to schematics.

One of the yellow wires is from the radio fuse in the I/p fuse box to terminal F2 at the radio,One is from the panel dimming fuse in the I/P fuse block to the F5 terminal at the radio,and the 3rd is the negative from the L/R speaker. I looked up for RPO codes UX3/UX7. Hope this helps