Lost memory i have a pioneer deh-p3600 in my car every thing works fine but when i turn off the car i loose all my preset stations and the clock looses its memory too can someone help

Car stereos typically have an "ignition" and a "battery" wire. The ignition wire is connected to your ignition switch, and only supplies power to the stereo when the car is turned on. The battery wire is connected directly to the battery, and always supplies electricity to the stereo -- even when the car is off. This maintains presets, clock, and other settings in your stereo.

It sounds like your battery wire was either not hooked up, or has come loose. On your stereo, a Pioneer, this wire is yellow. Locate the yellow wire on the wiring harness on the back of your stereo. This wire should be connected directly to your battery (or another source that gets constant +12VDC).