Chevrolet Repair: Electrical Wiring, inline fuse, chevy c1500

Question
I have a 98 Chevy c1500 Cheyenne pickup.  I would like to know how to wire up a new accesory device.  I want it to run only when the truck is running and to turn off when the truck is turned off.  The manual tells me it needs 10 amps.  I have 2 auxilliary bolts near the fuse box I could wire it to but they are hot all the time.  Any suggestions?

Answer
you can branch off a circuit that is not used often that only works with key on.  You may need a test light to figure this out.  Also there should be a large wire coming form the ignition that is key on b+ only.  If you use the large b+ coming frmo the ignition you need to install an inline fuse no larger than 10 amps....good luck