Ric:

The Bentley manual covers radio coding in Sections 90.32 -
90.34.

The basics four entering the four-digit security code for
reactivating the radio after disconnecting power is:

1.  Switch radio "ON"  (radio will not play, radio LED
displays "SAF")

2.  Push & hold AM/FM and the SCAN buttons (display changes
to "1000")

3.  Release AM/FM and SCAN buttons ("1000" remains on
display)

4.  Enter radio's security code using first four program
station buttons (code will appear on display)

5.  Push and hold AM/FM and SCAN buttons once again until
display changes to "SAF"

6.  Release AM/FM and SCAN buttons (radio display changes to
a station frequency, radio is now coded and plays.

(Note: After two incorrect attempts at entering the security
code the radio will lock up electronically (the display will
show "SAF" and not change).  You'll have to leave the radio
"ON" for approximately one hour  to re-attempt coding!

Hope this works for you,

- - George Chapman, 91 GL
    Lake Almanor, CA