va97runner

I'm about to install my XM reciever to my Alpine h/u. I should power the XM unit from the remote turn on lead from my head unit, correct?

Thanks

Mystickal

Almost definitely probably not.

Though there are many different models of XM radios, some of which have 2 power wires and some of which have 1 power wire.

If yours has 1 power and 1 ground, then definitely don't hook it up to your remote turn on lead. The remote turn on lead isn't capable of supplying very much current - it's basically a 'sense' line that tells an accessory when to turn its power on (eg amplifiers, EQs, some CD changers, and power antennas). All of these accessories have an independant power connection that supplies enough current for that particular device.

In fact, I've done installs where there were so many accessories hooked up to the turn on lead that there wasn't enough current to turn ANY of them on. Had to wire in a relay.

Now, if your XM receiver has 2 power wires and 1 ground, one that is marked PWR or something similar, and one that is marked RMT or something similar, then yes, you will need to hook up the RMT wire to the remote turn on lead.

Hope this helps,

~Bill

va97runner

Ok, my XM unit has one power and one ground wire.

So I should hook it into the yellow lead going to my head unit?

Thanks for the help.

Mystickal

You can, but a better solution would be to pull the power from a distribution block somewhere - for example, the fuse box or if you have a dedicated wire coming from your battery.

The problem is that I don't know how much current your head unit can draw, nor how much current your XM can draw, nor how much current the fuse that protects your radio can pass without blowing. It *should be ok. But it'd be better on its own circuit.

If you want more information let me know, but right now I'm just talking in general terms. Hooking up the XM radio to the yellow wire will pull power from the battery at all times, meaning that you can have the XM radio on and pulling power even if you don't have the key in the ignition. The red wire is the one that has power once you turn the ignition to on, so that may be a better solution. But as I said, it depends on your model - some models may require a constant hookup to maintain radio station presets.

~Bill

Eric

I wouldn't

If it is any type of newer alpine HU. they like having their own constant right to the battery (yellow is constant, red is ign)

the turn on lead cannot handle that large of a load. You could add a relay and have the remote turn on the relay that will then turn on the XM and whatever you have hooked up to it.

If you don't want to go through that, just hook the XM to any ignition wire. Make sure that the wire you are tapping into can handle the extra load of the unit, and length or wire run. PM me if you have any questions on that (too lazy to type it all out)

Mystickal

The only problem with that is that if the XM unit requires 12V from the battery to maintain its settings, then you don't want to hook it up with either a relay or ignition wire. If it doesn't require a 12V constant source though, than it would probably be better to hook it up to an IGN wire. Though it'd be better still just to draw it directly from the battery - most things in car electronics are isolated, but when you start adding stuff to different circuits, you can play havoc with the electrical system if things aren't isolated.

Yeah, you're not kidding about that. A lot of the newer HUs by everybody try to draw too much current if they're using the HU amplifier - the stock wiring is not very robust and often can't even handle THAT current draw, let alone other devices.

~Bill