QuestionI want to install an am/fm/cd head unit in the bed of my Dodge P/U truck. I have it modified internally for camping and fishing trips. It has a bench, a bed and cabinets. I don't know how to provide enough power to the back of the vehicle for the head unit, speakers, small tv/dvd player and 12 volt outlet I want to install. Obviously safety is an issue. Can you please provide some guidance. Thank you. Tony.
AnswerHi Tony,
Unless you're using a power inverter for the TV/DVD player, it doesn't sound like you need a whole lot of current capacity for the system in your truck. I'd suggest using an 8-gauge amplifier power wiring kit. This should include enough wire to run from the battery to the truck bed, along with a fuse and fuse holder to be located near the battery. I'd combine this with a basic fuse block, available at any auto parts store. You can run the power wire directly to the fuse block, then install individual fuses for each 12V accessory. Note that only the positive wire needs to be connected to the battery; the ground wire can be connected directly to chassis metal in the truck bed. You can combine all the various ground wires to a single ground bus, or ground each device separately at its location.
You'll probably need to run your power wire underneath the truck's chassis, and through some access point into the truck bed. If you're running the wire through a hole in sheet metal, you'll need to use a grommet or bushing so that the sharp edges don't cut into the wire's insulation. For the run under the chassis, I'd try to follow the factory wire runs; dress the power cable in split loom, and use cable ties to fasten it to the factory wire bundles at 1' intervals. This should prevent a sagging wire from hanging down under the truck.
If you're planning to use this for a long time with the engine off, you might want to consider a second battery in the truck bed. You'd need to have it mounted in a battery box, vented to the exterior. You'd also need a battery isolator system, so that the battery can be charged by the alternator when the engine is running, but won't draw down the main battery when you're using your radio with the engine off. If you're not adding a second battery, then you might want to install a battery voltage monitor so you can keep an eye on eye on the battery level--I'm sure you wouldn't want to be stuck out in the woods with a dead battery. (A solar battery charger might be a good thing to keep on hand, too, just in case).
Hope this helps!
Brian
