Benzben

I ordered a Harman Kardon Drive + Play 2, and I'm planning on hard wiring for power. I want a clean install and don't want to deal with a big cigarette lighter adapter sticking out all the time. (I'm also going to run it through the AUX input--big thanks to Sawloo and everyone else who contributed to the AUX cable harness DIY.)

I want to just use an Add-a-Circuit to tap into the driver's side fuse box rather than splicing any wires (probably the cigarette lighter...where I would not even know which wire to start cutting). The power cable included with the Drive + Play has three separate wires: constant 12V power, a 12V ACC wire, and the ground. If I connect the constant 12V to the Add-a-Circuit and then tap into a fuse slot that is connected to something that only gets power when the key is turned to the ACC position, do I need to worry about connecting the ACC wire? Do I just cap the D+P ACC wire off and rely on the fact that the power going to the fuse slot will take care of the ACC/constant issue? Or do I need TWO Add-a-Circuits, with one connecting the D+P constant wire to a slot with constant power, and the second connecting the D+P ACC wire to a slot with ACC power only?

Also, if I'm not cutting and splicing any wires, do I need to worry about disconnecting the battery? Or can I just connect everything and then plug my Add-a-Circuit into the fuse box? I've read about some nightmare reset/resync stories when people have disconnected their batteries to install new ones, for example.

Thanks in advance for any help. I searched but couldn't really find a good answer to this sort of question.

kevblah

To the best of my knowledge, I believe the whole fuse box in the front is a constant power source. I know this because I've tapped everything in there with the car off and have been able to receive power.

Benzben

So the ACC power is only available at each of the sources (like the cigarette lighter) that use it. I should still be able to just wire the constant 12V on the D+P to the fuse box and get power normally, right? Meaning, just like everything else, it's not going to draw (too much) power (and therefore drain the battery) when the car isn't running. I think. If not, then I'll have to see if I can figure out which wire is which behind the lighter and take a chance on cutting and splicing.

Maybe I should have gone to an MB tech school instead of law school. Probably would have been more fun. And it would HAVE to be cheaper.

jedcred

I'd say go with the cigarette lighter ACC wire for your ACC power, if ACC power is what you're looking for. You shouldn't risk something being constantly on when it shouldn't have to be, even if it does draw low power.

Also, to make it easier, you don't really need to splice by hand. Radio Shack has snap-in wire splicers (they're blue) that makes that sort of thing really easy and clean.