i'm putting a cd player in a ford rancharo, and it doesnt have any wirers for a head unit. i need to know where to connect my power and memory wire to a power source.
You can hook up the battery constant straight to the battery, that is what I have done (I used 8 gauge wire-overkill, especially since I'm not using the internal amplifier-10 gauge should be fine for your scenario). The memory wire brings up a good question...of course there is always more than one solution to everything but the best I can think of for now is hooking it up to the battery as well, then placing a switch in-line to turn the unit off when you get out of the car so that the battery does not run down.
A relay would do the job. Take the wire that you'll run from the battery and split with a distribution block. Send one side to the HU wire that always needs a constant power source and send the other wire to a relay. Now all you need to do is find an appliance in the car that's only on when the key is turned. Break into that power wire and connect another wire to it with a 1 Amp inline fuse and send that to the relay. The final wire coming out of the relay goes the head unit, to the wire in the harness that is only powered when the keys are turned. This way, you won't have to worry about forgetting to turn it off and the HU draining the battery. If you're pretty handy this won't be too tough or you could always pay someone to do it. Have you figured out where you're going to put the HU?