Need advice regarding power connections for mobile electronics

Eric Pennal · Mar 16, 2006

What is the best way to connect multiple A/V components to a switched accessory power source? There appear to be several options, but what do some of you A/V experts prefer (wire color and location)? Is there a place under the dash or fuse panel you have found easy to access?

I'm planning to install a DVD player in the center console, with a monitor control box, A/V Selector, Nav unit, and rear-view camera mounted in the rear cab area. Rather than run all five units' power wires up to the front and tap them to a switched power wire (probably under the dash somewhere with limited space for taps), I thought I could make a single tap on the power wire and run an extension wire under the console, through to the back seat - creating a power backbone, so to speak. I could do the same thing with a ground wire I already have bolted to the frame, for my ground connections. This concept would let me run two wires from the front to the back, as opposed to ten wires. Would this work?

Thanks.

Todd Z · Mar 16, 2006

I would run a relay under the dash, and connect everything to that. A nice 30 amp relay should do the trick. That would allow you to tap the fuse box off any keyed power and not worry about load..

Run 1 nice size wire from the battery to the relay and tap your accessories from there..

Todd Z

Fudged Undies · Mar 16, 2006

What Todd said.

Eric Pennal · Mar 16, 2006

Thanks guys.

Todd, just trying to understand your recommendation for a relay here. I'm not as knowledgeable as you are about this stuff, but every time I've used a relay, it's involved adding a switch to energize the coil side of the relay which closes the circuit side of the relay to the component, providing power to the component. This requires splitting the incoming power to two pins on the relay (the coil circuit side and the component circuit side). It sounds like you're describing a way to turn an "always hot" circuit into a "switched hot" circuit going out to the components.

If I tap a "switched" accessory power source for my power backbone, would I still need a relay? Or are you recommending a relay because I'm trying to tap too many devices to the same circuit?

Todd Z · Mar 16, 2006

I am recommending a relay because you will overload any of the ST stock circuits with all that stuff...

Do as you said, Switch a fused constant direct feed from the battery with the relay, BUT let something in the truck be the trigger rather than a switch, can do a tap from the fuse box for that...

Basically take a (+) lead go to 1 side of the load on the relay, Than run all the (+) feeds from the equipment to the other Load side. Ground the relay, and then let the other (switched) side get triggered by something in the truck, No need for an extra switch..

Todd Z