I need to power my XM radio and want to hardwire the transformer directly to a 12v supply that is hot with key on.
Does anyone have a wiring diagram or suggestion?
Thanks.

 

Open your owner's manual to the section on fuses. Identify a fuse that is HOT IN RUN (you should know which ones are based on operations).

Remove fuse, locate the supply side with a meter, then install a fuse tap (available from Radio Shack) on the fuse when you reinstall it.

NOTICE: The fuse tap will stretch out the connection in the fuse panel. If the tap is later removed, you have to make certain the fuse can now make solid contact in the fusebox. Usually, it's just better to leave the tap in place.

Otherwise, just pull the factory radio and use an inline splice to tap into its supply.

Steve

 

Why do you want the xm to loose power when you turn your truck off? I'm not making fun of ya, I just want to know.....

 

Thanks Steve. I just tapped into the stereo power supply.

My XM has a built in battery which would charge with the key off. I don't need that 5v transformer being powered when I take the XM into the house or if I leave it in the truck I wonder if the drain will have any affect on tripping my aftermarket alarm. Plus, I can't listen to the XM in the truck without the stereo on anyway.

Thanks for your comments.
John