Ok, I'm having a brain fart here. I'm hooking up a sirius tuner and an HD Radio tuner. Both boxes require a power source, so instead of splicing into the radio harness, I was thinking of adding an add-a-circuit into the 12v accessory plug fuse holder in the fuse box. Could I run them both off of the same add-a-circuit or would it be better to seperate them and put in two add-a-circuits?

I'm thinking they use switched power, like the accessory plug, and the headunit saves all of your presets and things.

 

bump bump bump anyone?

 

Most head units need a switched and a unswitched power source. The unswitched source is used to keep the settings of the headunit in memory and to run the clock if it has one. The switched source tells the headunit when you've turned off the vehicle so that it will power down as well and it's powers up when you start the car or turn the ignition to the accessory position. I'm not sure about the Sirius radio and how they hook up. You can use the accessory plug as a switched power source since the head unit only uses it to sense when the ignition is on or off. This is assuming that the accessory plug is powered on/off with the ignition system.

 

So since the HD tuner and the Sirius tuner boxes both require power, can I run them off the same add a circuit and just put a larger fuse in there? I was going to wire it up to the 12v accessory since I don't use it for anything else and its switched power. I didn't want to run the Sirius and HD tuners off of the headunit wiring.

Any thoughts about the best way to hook everything up?