I plan on installing a Kenwood DDX7015 into a tC. I already have the Metra wiring harness needed for a Scion and I have been studing the PDF insructions for the Kenwood. All the wires from the Kenwood match the wires already in the car, except the Kenwood wires have 2 yellow battery wires and 2 black ground wires (while the car's harness has only one of each.)

The question is can I do a Y-type connection from the 2 kenwood yellow battery wires into the stock single yellow battery wire connection in the car. Can I also Y-connect the ground wires? If not, I assume one wire stays with the harness and the other goes straight to the battery (or fuse box). And the ground goes to a grounding point.

Here's the pdf if you want to see what I mean (page 107/10
http://akamaipix.crutchfield.com/Man...113DDX7015.PDF

 

Yes, you do the 'y connection'. put both yellows from the radio harness to the one from the adapter harness.
same deal for the grounds.

 

I forgot to mention that one of the yellow battery wires from the kenwood has an inline 5A fuse in it......will that matter?

 

That does not matter, just keep the fuse when you make the connection.