Not totally understanding Upfitter switch wiring

[figure1a]

Why are there two sets of wires under the hood by the battery? Reading below, it says set A is powered—OK, I get that. What is set B for? Just a set of wires that have already been through the firewall for me in case I want to power something inside the cab?

 

[heyitsfish]

Why are there two sets of wires under the hood by the battery? Reading below, it says set A is powered—OK, I get that. What is set B for? Just a set of wires that have already been through the firewall for me in case I want to power something inside the cab?

Yes that is correct.

Want to run external lights? Then just connect them to the powered "set A" under the hood and you are good.

Want to run a radio/device inside the cab? Then connect the same color wire A and B under the hood and that corresponding wire in the footwell will now be powered and run off the corresponding Aux switch.

 

[figure1a]

Well, schit. That was easy. Thanks.

 

[4wheelinAZ]

And Red taped wires are your ‘hot’ wires, and the white taped wires are your footwell wires

 

[figure1a]

Here's another question for you. Most of what I will wire will need a relay for more power. Are there convenient unused connections in the fuse box or am I going to have to wire my own stuff up directly to the battery (fused, of course)?

 

[The Car Stereo Company]

Here's another question for you. Most of what I will wire will need a relay for more power. Are there convenient unused connections in the fuse box or am I going to have to wire my own stuff up directly to the battery (fused, of course)?

go to the battery. most direct and wont interfere with the trucks wiring. going through the fuse box can cause issues especially with warranty related work. keep it simple and wire direct.