How do I set the radio stations on my P9628b radio. I'm setting them but they aren't staying. I'm having to reset them each time I turn the truck in

There is 2 different radios. With or without rds. Here are the instructions for both.
Setting the Time for Radios with Radio Data Systems (RDS) To set the hour, press the clock button. The clock symbol displays and the hour flashes. Turn the ADJ (adjust) knob to increase or to decrease the hours. To set the minutes, press the clock button again. The minutes. Turn the ADJ knob to increase or to decrease the minutes. The time can be set with the ignition on or off.
To synchronize the time with an FM station broadcasting Radio Data System (RDS) information, press and hold the clock button to enter the clock set mode, then press and hold the clock button for three seconds until UPDATED displays. If the time is not available from the station, NO UPDATE displays.
RDS time is broadcast once a minute. After tuning to an RDS broadcast station, it can take a few minutes for the time to update.
Setting the Time for Radios without Radio Data Systems (RDS) To set the hour, press the clock button. The clock symbol displays and the hour flashes. Turn the ADJ (adjust) knob to increase or to decrease the hours. To set the minutes, press the clock button again. The minutes flash. Turn the ADJ knob to increase or to decrease the minutes. The time can be set with the ignition on or off.

hi, does the radio go back the standard settings when you turn off the key, if it does than try checking the fuse for the constant power supply as this controls the time memery and the settings for the stations, if not try holding the station button down for 3 to 4 sec
hope this helped

Without Radio Data Systems (RDS): To set the hour, press the clock button. The clock symbol will appear on the display and the hour number will flash. Then turn the ADJ knob to increase or todecrease. To set the minutes, press the clock button again. The minute numbers will flash. Then turn the ADJ knob to increase or to decrease. The time can be set with the ignition on or off.
With RDS: Same as without RDS unless you want to Sync. with a radio station. To synchronize the time with an FM station broadcasting Radio Data System (RDS) information, press and hold the clock button to enter the clock set mode, then press and hold the clock button for three seconds until UPDATED appears on the display. If the time is not available from the station, NO UPDATE will appear on the display. RDS time is broadcast once a minute. After tuning to an RDS broadcast station, it may take a few minutes for the time to update

setting stations on Fords are easy,put it on the station you want to program and push the channel button in and hold for about 2 seconds then it should flash,now the channel is set..now for the clock,with the key on and radio turned off,press the clock button,then press the seek or scan forward or reverse to adjust the time,then hit the clock button again to make sure it sets.

The setting are in your owners manual. usually there is a menu on the radio that has settings. either by holding in one of the set station buttons....or by holding in the tuning buttons...

Just make sure your radio is turned off before removing the battery. If the radio is on and the battery is removed and replaced, the radio may get locked out. This will prompt you to enter and reset code to your radio to have it work again. Good luck and after you battery has been replaced, just reset the radio stations setting and time. 

just like any computer, unplugging it for 30 seconds or so may cause it to revert to initial settings.... if you take the battery terminal off you will reset everything and that is not necessary.... find the fuse for the radio and yank it.... see if it helps. IF NOT, probably a burned programming mode... hope you like that station....

usually just holding down the # you want to have the preset station at will set it

Take out the radio. Remove the nickel. Reassemble and reinstall. Next time feed it krugerand.