NMK5, What have you got, your own radio station in that pickup? It sounds like you've got it all handled quite well and it seems to work for you. But in all my years as a mechanic the wiring was the one thing do-it-yourselfers seemed to muck up worse than anything else.And usually a hot lead off a battery post was a red flag to a greater misunderstanding of basic electrical principals elsewhere in the car. Over the years I saw very few accessories installed properly with a clean wiring job and proper circuit protection, adequate wire size ect. I am not saying yours isn't well thought out but I still wouldn't wire any accessories direct to the battery. Not only will the connections usually corrode off but you also have to remember to turn everything off when you park.

 

Yep, exactly. It's a rolling radio station. Yep, I see your point, and agree as it pertains to most peoples wiring. Myself, in general I hate butchered up wiring. All my ford wiring is totally stock. But it's actually the best way to go in my case for the radios. But I have both + and - wires coming back. I don't use the truck body as power ground to the radio as that would defeat the purpose of using the thick copper wire, and low resistance connections. Not to say the body couldn't do the job, but it's better to use the wire. It's a known quantity as far as it's resistance. The car body could be all over the map depending on how it's connected, rust, corrosion, etc.. Also both + and - MUST have fuses inline in a case like this.
The voltage to the radios is pretty critical. You don't want a large voltage drop from too thin a wire, or resistive connections. The radios get unstable and can "FM" , "chirp", or other problems. Just a stock 100 watt output radio needs a stable voltage 20 amp supply.
If I ran a solid state 500w amp, I'd need 80-100 amps easy. But I usually just run 100w. I have to use at least two paralleled batteries to run an amp, and it's best to have a super heavy duty alternator, or it will be toast before too long trying to keep the battery charged. 100w is much easier to deal with. MK

 

Sounds like you have learned about dc courant from experience, like I did. Most people don't give enough attention to ground connections. I have solved many weird electrical problems just by running a couple ground wires. For some reason many people fail to put the original ones back on after any major underhood work.