wiring questions

I am installing new component speakers and an amp in my '96 2 dr. Yukon, and I need a little help.

First,  I am using the factory head unit, so I have to install a LOC. The LOC I have is 4 channels, 2-front 2-rear. My truck is wired for a component set, so I have a total of 4 signal wires for the front. 2- tweeters, 2- 6 1/2's. Should I wire the LOC using all 4 signal wires by splicing 2-into-1?  And/Or, should I wire the LOC directly behind the head unit, or on one output side near the door (Right/Left)?

I'm not sure what the wiring coming out of the head unit looks like, their may be a crossover/amp between the head unit and the speakers? Anybody know?

Second,

                  I am using an older RF punch 45.2 amp (2 channel) to power the new components. My new speakers come with passive crossovers that give the option of either 1 or 2 channel input, 2 channel output. Since my amp is a 2-channel amp, should I wire it how it was designed using the one channel option ; or is it okay to have 2 wires on each (-) and each (+) output terminal on the amp, and use the 2 channel input option on the LOC?

Okay, one last question, this one should be easy. Is it alright to connect the amp power wire to the threaded studs on the side of the fuse box? The studs do have power, I checked. I have always thought that amps had to be wired directly to the battery, but these studs look like they were designed for this kind of application.

If this is too confusing I can take pictures of all of my gear and post them. You know what they say, a picture is worth a thousand words.

         Thanks for any help ya'll can give!

It's usually "cleaner" to wire Line Output behind radio, but some people like it easy.  I usually use the Rear channel outputs for the AMP and U could use the "Studs" U are refering to, but they are fused at 30 amps inside Fuse box.
Depending on size of AMP I usually use the Battery wire on box or run wire to Battery for large AMPS

NO there is not a cross/over amp from factory

Thanks man,

                        Do the rear channels carry the same signal freq's as the front? I thought that there was some kind of x-over in the head unit. My amp is rated for 60x2 rms @4 ohms, according to the specs. so the fuse box option is the way to go i guess. For the LOC, does it affect sound quality to wire in only one side? (right or left) 

Thanks again for the help.

You have a 4 channel LOC, so you will wire it to both front and rear speaker wires, using both left and right.  It is simplest to do this behind the head unit, if the factory wiring is there.  Then run two sets of RCA's to the area where you will be installing your amp.  Use the front RCA's for connection to the 2 channel amp, and tape off the other unused ones.  Now they are there if you decide to upgrade the system with an amp for subwoofer.

You need an 8 gauge wire connected directly to the pos battery post.  Put a fuseholder inline within a foot of the battery and fuse the wire with a 30 or 40 amp fuse.  If you are planning ahead for a possible upgrade to include a sub, use a 60 amp fuse.  The wire will take up to a 80 or 90 amp fuse.

Set your crossover to the 1-channel option.  The 2 channel option is for biamping the components, which would require a 4 channel amp for 2 sets of components.  Run one set of speaker wires to each crossover.  The crossover will distribute to both the tweeter and woofer.

I appreciate the helps guys, I have everything installed and it sounds great! I ran the amp off the fuse box to make things easier, and put the LOC right behind the head unit. I'm glad I ran the extra RCA's because I definately need a sub now. I'm thinking that a single 10" will work well. Any ideas for a good stealth type enclosure or any suggestions for a sub/amp combo would be appreciated. The components sound great, but the lower freq's just dont come out in the 6 1/2's. No surprise there. It did take me a while to get all the wires run, rca's and rem power, etc. but it looks like I had it done professionaly and sounds that way too. Thanks again! I can take a few pics if anyone cares how it came out...