As you look at the wires for the radio you should have a blue wire with a yellow stripe, This is a full time power lead direct to the battery through the dome lamp circuit.
There is also a gray wire which is the switched power to the radio this is fed through the cig-rad fuse. The brown wire is ground for the system.
With the key off you should have power to the blu/yel wire with your light ground connected to the brown wire (or a good ground, test both as it could be a bad ground) If not and the dome/interior lights are not coming on then check the dome lamp fuse (20 amp, located in the fuse/relay box) for power on both sides.
Next check the power from the gray wire to the brown (and a separate ground point as well) with the key on. No power there? Does the cig. Lighter outlet work? Check the cig-radio fuse for power on both sides with the key on.
If you have no power to either wire and no power at either fuse I suspect the connections inside the fuse box itself have corroded or the feed wire to them has.
Post back with the test results and we can go farther if you do not mind removing the junction boxes and checking the connections. Or if you just want sound you could bypass the factory wiring. Just be aware that the power for both radio feeds also feed other items which could fail over time if the wiring gets worse.
Sunday, December 4th, 2016 AT 1:41 PM