I should have been more explicit with the meaning of radios, sirens and lights. I'll only be powering up 2 radios and a repeater (which i think gets its power from the radio), a simple siren, and a few LED lights. I've heard of the isolators of which you speak of but I'm not running that much equipment to install a 2nd battery. Being this is my first Dak, i'm just not familiar with its electronics and such to steal power from. Basically, I want the radios, siren and lights to run only while my ignition is on. Otherwise, everything will be powered off when key is in the off position. I'm planning on installing the radio, repeater, siren box under the rear seat but dont want to run multiple power feeds for each. One power feed for all equipment to a distribution block then branch off from there. Where do i get the power feed from?

 

I'm confused alright. *g*

I'm getting mixed messages about what you want to achieve.

Your concern about "killing the battery" led me to believe you wanted some sort of isolation -- which can ONLY be achieved with a second battery.

Even if you opt to forgo the isolation, I would think you'd want the comm equipment and emergency lights to remain powered even when the ignition is OFF -- unless/until you turn the radios or lights themselves off. That's how I prefer my radios to work, so that I may leave them ON in camp or at a lunch stop WITHOUT leaving the key in the ignition and all other vehicle accessories powered.

It should be a relatively easy thing to run a heavy (say, 10 gauge) power wire directly from the battery, through the firewall, under the door sill trim and to a distribution block under the rear seat as you describe. Add up the amperage loads of all your devices and fuse this power lead appropriately as close to the battery as possible. Then fuse each individual device separately as well.

If you're really sure you want power only when the ignition is ON (which will force you to leave your key in the unattended vehicle), you might be able to pick up the switched power you need from the power seat harness. I don't know this for a fact, but I'm told it's there under the carpet even if you don't have the power seat option installed in your truck. It should be pretty heavily fused. You run a risk, though, of confusing the rest of the CANbus system by putting an unanticipated load in an unanticipated place. All sorts of unpredictable side-effects can result -- all of which will be avoided by wiring directly to the battery.

Does that help?

 

Yes it does help, thank you!! I thought maybe there was another way of getting power without having to tap directly into the battery but I asked around again in my FH and sure enough they all said to tap directly into the battery. My other Chief's keep their personal vehicle running while on scene unless its a big job then they just shut the whole thing down. We cover a 5 mile portion of I-95 and get plenty of fender benders and keeping the truck running with the lights and radios on is a big plus for us!! Thanks again Brand!!