custom truck mods

Blue Sea 6-gang marine-grade 3AG fuse block

Closeup of the fuse block	Overview of the installation
Notched battery terminal cover	Battery wiring detail

over-engineering?

After some of the wiring that KC HiLites provided with their KC DayLighters started to have a meltdown, and looking ahead at the lighting I plan to install, it became clear I needed a new solution. I decided on an ultra-clean, high capacity solution as I was looking at a total current draw of 970w (81A total) consisting of four 150w KC DayLighters on the roof, two 55w floods out back on the rack, and two 130w fog lamps on the front bumper. I might mention the stock alternator puts out 90A!

the fuse block and wiring

I decided to clean up the wiring that had already accumulated from installing the two sets of KC DayLighters as it was, and to plan ahead for intalling another pair on the roof facing forward and a pair of floods facing towards the rear. Something better than inline fuse taps and long individual power leads from the battery was needed. Using 8 gauge marine-grade cable to and from the battery, the fuse block can handle a total of 100A with 30A per circuit. I went with the glass style fuses over the ATC type because you can have fractional amperages - which might come in handy for electronic circuits I may install at some point (MP3 server, digital video/photo equipment, etc.). Plus the form factor and specifications were more to my liking. I may upgrade the 8 gauge cable to 6 gauge but this combination should handle my current and near future plans nicely, since the cables are <2' long, they don't have to be that heavy. I do plan to replace the battery terminals with some nice competition audio-grade stuff I've been eyeing. Just to clean up the battery area and make it ultra sano.

Each relay is fed from the fuse block via a <6" 10 gauge wire and from the relay to the lights as well. Connections are non-insulated crimp on with heat shrink tubing over the entire exposed connector. These connections will later be soldered, as well. Plastic conduit covers all wiring within the engine compartment for an extra measure of safety and protection - as per stock. The ground wires were also kept to an absolute minimum with the same specifications as per above. They all run individually to a ground bus on the fuse block, which runs back to the battery. I could have taken the ground cable to a spot on the engine compartment sheet metal, but why not make it dedicated straight into the battery? I wanted a dedicated, clean connection for these high draw lights which may end up on a dedicated battery at some point, along with a winch (though that has to be powered right to the battery itself). Over-engineering. You betcha.

what's next?

The relays in the picture will actually double in number and be mounted on a custom made aluminum bracket, with wing nuts to facilitate relay replacement. This mount is currently being hand fabricated. Therefore, the wiring arrangement is not final in this area. More signal, power and ground wires need to be run as well. But the power distribution problem has been solved!