Hi i turn my alpine on and i have 2 retune the

Probably you dont have the constant pos (+) wire hooked up to hot (+) wire and only to a source that is switched. Switched means every time your key is removed from ignition switch the positive current from that source will also power down. There are two positive leads from the unit, 1 always hot and the other needs to be switchable. The constant hot (usually yellow) powers the memory for your settings. Just like your television set, once you pull the cord off the socket everything returns to default setting.