Help please!

I've a '04 Mondeo with the standard fit Sony / Ford(?) 6-CD player /
Radio.

The Audio Manaul supplied with the car makes no mention of this unit &
subsequent enquiries with ford dealer parts depts. havn't been able
source a suitable manual.

Do I need to contact Sony, rather than Ford?

All I'm trying to do is persuade the unit to hold & display the RDS
time!

TIA, David C.